Brief Summary of Minutes of Annual Meeting

8:35 a.m.

Mark Bennett: Call to order and opening remarks.

Introduction of participants.

Mark: 1) Report on the state of W-2168 membership; 2) approval of 2010 minutes: approved by Daniel and Greg; 3) Outgoing leadership: Hector Perez (FL) is stepping up to President position; and Xingyou Gu (SD) is moving up to vice-president position; and 4) the next host site selection, plus nomination (secretary-elect) committee: Bob and Mark were appointed; Hector (FL) has offered to host the next annual meeting; time to be determined.

Other topics discussed: Recruitment of new members - young faculty, graduate students, and research associates. Funding for graduate student travel. Budget considerations at individual institutions: CRIS or Hatch funding.

Manjit: Introduction of Dr. Joe Colletti, Sr. Associate Dean of ISU College of Ag and Life Sciences.

Dr. Colletti Statement of support: Ag Experiment station sees value in research collaboration. "Scope out the frontier--where should the science go?" Ethanol is 1st generation in the biofuel-economy; Soy is the 2nd, with oil used in biodiesel; The paradigm shift in agricultural industries; Dry distiller's grains no longer waste product, but a co-product, etc.; Working with the producers and public sector: Range of involvement = economists, engineers, scientists, producers, etc.; Funding for facilities is available.

Questions for Dr. Colletti: "What examples have you seen to keep the seed science faculty and student positions [participation by industry]?" Joe: Recognize that if land grant institution programs thrive, Pioneer Hi-Bred et al. will benefit. Some opportunities present in an inorganic manner. Manjit: strong support, response to workshops, good interactions with industry. Joe: pay attention to the orphan crops. i.e., many apple orchards dropped out of production because of weather challenges, upswing in production of crops due to introductions of hybrids, etc. Resurgence of formerly-major crops now. Push for shipping seeds, not plants. Inclusion of smaller companies is important, too.

Bret Hess (W-2168 Admin. Advisor):

1) Name change for review committee (was RCIC, now MRC - multi-state rev. cmte.)

2) Single submission deadline for ALL proposals, 15 January: New & renewals, Summer review, Approval during summer meetings, Fiscal year for federal govt. in October.

3) Implication for W-2168: renewal must be submitted in 4th year; Engagement of stakeholders, industry reps, and inclusion of new members is acceptable; Important: must demonstrate progress for this to be acceptable for renewal of proposal.

4) Advice: 10 July 2011 is date of next RMC. W-2168 is topic on agenda; our project seems to be stable; Review progress.

5) Questions?

a. "What about the next rewrite. The previous was quite extensive". Explanation of review process: Peer review, MRC review. Some projects overly ambitious. Streamline proposals to minimize rewrites. Need to submit a report on W-2168 progress.

b. "Since you have been involved..submissions that are not accepted..is the bar raised?" Can't recall any declined outright. Most are revised first. Governance outline is not necessary&be mindful of what is required. This group has been successful, so no problems anticipated. Some advice may be provided to this group. Proper use of terminology, 'milestones', 'outcomes' vs 'outputs', etc.

c. "Is there a national project?" This is considered a national project. This group is based in western region, but the projects are open throughout the region. It just happened to land here. Not sure how that happened- likely linked to extensive seed production/research activity on west coast years ago (and ongoing). The higher level function is not filled by this group, which is a research group. The reason for the western region is that this group started in the western states originally. As other seed people from other states joined or left the group, the shift in group locations shifted over time. Some of the things that we seem to have excelled in are educational programs. We can discuss how industry sees us as a pipeline.

d. Research is the first priority for this group, but should we tout the number of students as output for this group? RMC & include outreach as part of an objective. RMC is starting to see a trend in a formally-structured education objective, either through outreach/extension or education. Some groups would invite stakeholders to participate in group, i.e., invite Pioneer to W-2168 meetings. The more broad, the more global, the better the reception [to this proposal].

e. "The new project..will we need to prepare the proposal for the next project in 2012 or 2013?" Prepare in 2012, so if revisions are required, there is time to revise. Otherwise, the 2013 deadline may be missed, funding not granted, and this group runs the risk of being inactive.

f. Final advice: the report for this meeting is due within 60 days (September 8). Remember the form indications are limited, so streamline the report. Last year's report was too lengthy.

g. "How do we update our participation list?" Give Bret a list, so he may contact their AES for inclusion or removal, or work with your institutional AES to update that information.

h. Even if each institution supports only 1 designated official member, it would be acceptable to bring additional representatives but keep the 1 designated member. Representation of each state from more than one institution would be favorably viewed (i.e., one rep from each land-grant, one rep from an additional univ. or agency).

Introduction of new attendees.

Daniel: Brief introduction of South American and African countries contacts.

10-minute break, then state reports.

State report:

1. Bob Geneve (KY): 1) Overview of UK group: Bruce Downie , preparing for sabbatical leave; Jerry Baskin has retired; Carol will retire soon. 2) Research report on searching for the water gap in seeds with physical dormancy.

2. Xingyou Gu (SD): 1) Genetic and QTL analysis of seed dormancy and pre-harvest sprouting in synthetic wheat; and 2) cloning and molecular characterization of QTLs for seed dormancy rice.

3. Lin, Liang-Shiou (USDA-NIFA): Introduction of NIFA structure; 5 challenging areas. Questions: NIFA collaboration with NIH and other funding agencies.

4. Greg Welbaum (Virginia Tech): BARD project: control of bacterial fruit blotch of cucurbits using the maize non-host disease resistance gene Rxo1. BARD funded by Israel. BFB Bacterial fruit blotch caused by Acidovorax avenae. 600 lines of watermelon identified for responses to the disease. Cold tolerance: base germination temperature of Cantaloupe seeds. Drying seeds using clay beads for tropical crops.

Lunch

Tour laboratories of Seed Sci. Center.

Afternoon state report:

5. Lisa Shepherd (ISU): Intro. of National Seed Health System (NSHS) & phytosanitary efforts.

6. Gary Munkvold (ISU): NSHS, methods development. Seed borne diseases in corn and soybean. Graduate program in seed tech and business. Online delivery of teaching programs.

7. Daniel I. Leskovar (Texas A&M): Improving transplant quality and stand establishment of vegetable transplants under biostress. Does ABA protect watermelon seedling from chilling injury when transplanted in early spring? Stress tolerance of pepper (Colima)-leaf chlorophyll. 2) ABA: height control on pepper and watermelon. ABA staging expt. with watermelon. Crop protection from deer damage. Yellow nutsedge: chufa.

8. Hiro Nonogaki (Oreg.St.): a) Hormone metabolism in seeds; plant gene switch system (PGSS), promoter+NCED6 induced by chemical. Ligand:methoxyfenozide NCED6 induction; ABA deactivation system or GA biosynthesis GA3 ox1. ABA perceptation and signaling. Seeds III - Coming soon.

July 9, 2011

8:27 am: Call to order. Distribution of contact information. Final points before beginning today's business.

State reports (cont.)

9. Peggy Lemaux (CA):

1) Brief report on accomplishments from Kent Bradford's group: Identification and characterization of biophysical, biochemical, genetic, and environmental factors regulating or influencing seed development, germination, vigor, and dormancy in lettuce. LsNCED4 is essential for induction of thermo-inhibition in lettuce seeds.

2) Modifying expression of thioredoxin in cereal seeds to improve grain properties including PHS (UC-Berkley).

10. Alan Taylor (Cornell Univ.- Geneva): Seed dormancy in switchgrass; Seed sci & tech controlled release of seed treatments; seed conditioning of warm season grasses; introduction of rotary pan coating tech. Microcrystalline cellulose infused with Rhodamine B as colored and fluorescent tracer.

11. Keting Chen (Graduate student in ISU Seed Sci. Center): Cellular mechanisms of seed osmopriming in spinach.

12. Mark Bennett (Ohio St.): Relationships between internal morphology (esp. % free space), germination and vigor of Portulaca grandiflora and Portulaca sp seeds, using non-destructive x-rays and scanning software

Final discussion:

1)Site selection for the next W-2168 annual meeting. New president (and host?): Hector Perez (FL); time: Jan, Feb or Mar. 2012 ; survey membership for best dates; location: pending details from Hector.

2)Report of secretary-elect - Manjit will recruit for position from ISU colleagues.

3)Free discussion:

Manjit: Distribution of presentation list/speaker schedule before the conference; make the meeting available to graduate students; get industries & ARS people involved in the meeting.

Greg: W-2168 symposium every ~ 4 years to have industries involved.

Manjit: invite other seed groups to the meeting.

Bob: Feedback from seed industries for new issues to be addressed by seed researchers.

Manjit: milestone accomplishments, add/combine symposium to W-2168 annual meeting.

ISU seed sci. 2012 spring (and annually) symposium.

Alan: Recruit young seed researchers to W-2168.

Bob: Invasive species researchers; Germplasm groups.

Greg: Proposal of 'seed CAP', potential areas such as seed health. Match funding for seed pathology from other industry partners?

Lin: This community is a stake holder (inclusion of seed develop/health/biology in USDA NIFA RFA)

Manjit/Peggy: additional seed sci. education opportunities (e.g., games/web info) to high school students.

Adjourn at 11:00am

Objective 1. Identify and characterize biophysical, biochemical, genetic, and environmental factors regulation or influencing seed development, germination, vigor and dormancy.

Dr. Pablo Jourdan continues as Director of the revitalized Ornamental Plant Germplasm Center (OPGC), a partnership between the USDA and Ohio State University. The OPGC's research program explores factors that influence long-term seed storability for germplasm preservation. Peter Zale (PhD student) is using the core collection of 243 Phlox accessions to study seed biology potential for interspecific hybridization. (OH)

We have characterized a major quantitative trait locus (QTL) termed Htg6.1 associated with the ability for lettuce (LACTUCA SATIVA) seeds to germinate at high temperatures (up to 37 C). Genetic mapping identified a candidate gene (LsNCED4), which encodes an enzyme in the abscisic acid (ABA) biosynthetic pathway (9-cis-epoxycarotinoid dioxygenase 4). Functional complementation of Arabidopsis mutants in homologous genes demonstrated that LsNCED4 has the expected biosynthetic activity. Lines having mutations in LsNCED4 were isolated and their seeds were able to germinate at much higher temperatures than their isogenic control lines. Silencing of LsNCED4 in a thermosensitive line of lettuce (cv Salinas) using RNAi enabled seeds to germinate at temperatures up to 40ºC. Transferring the promoter and coding region of LsNCED4 from a thermosensitive line into a thermotolerant line resulted in the induction of thermoinhibition in seeds of the latter. These results confirm that LsNCED4 is essential for the induction of thermoinhibition in lettuce seeds and that reducing the expression of this gene can enable germination at high temperatures. Transcriptomic analyses identified clusters or modules of genes that exhibit correlated expression patterns in association with high temperature inhibition of germination. A second RIL population is being mapped to identify additional Htg QTL. A strong QTL on chromosome 9 (Htg9.1) is being fine-mapped to pinpoint candidate genes. (CA - Davis)

This project has supported research to identify the causes of seed dormancy and seed desiccation intolerance (recalcitrance) of the marsh grass, Spartina alterniflora, which is an important component for successful maintenance and remediation of Louisiana coastal stabilization. Two manuscripts were prepared and submitted; one has been accepted for publication and the other is in the process of peer review. New data have been collated in preparation for two forthcoming scientific meeting abstracts/presentations. The results obtained have been incorporated into lecture materials for undergraduate and graduate level courses, presented each year. The project has also supported the research training of one doctoral student (seed physiology, biochemical techniques, and mass spectroscopy) and one undergraduate (seed physiology and scientific method). Services included advising faculty and students in the LSU AgCenter Coastal Plants Project concerning development of seed germination protocols for various marsh plant species. (LA)

Bimolecular fluorescent complementation and protein pull-down assays identified in vivo interaction between PHYTOCHROME INTERACTING FACTOR1 (PIF1) and COLD TEMPERATURE GERMINATING10 (CTG10). (KY)

Using phage display and biopanning to identify protein interacting partners of PHYTOCHROME INTERACTING FACTOR1 (PIF1) bound to the promoter of GA INSENSITIVE (GAI). (KY)

Identification of the water gap mechanism in Geranium carolinianum. (KY)

Continued investigation of direct targets of the MADS-domain protein AGL15 in control of somatic embryogenesis has identified components of ethylene and auxin biosynthesis and response on promotion of somatic embryogenesis. (KY)

Development of tools and techniques to identify direct targets of FUSCA3 and ABI3, two transcription factors important for seed development. (KY)

Generation of transgenic Glycine max ectopically expressing MADS-box genes to test effect on promotion of somatic embryogenesis in this species. (KY)

Identify quantitative trait loci (QTL) associated with seed dormancy and pre-harvesting in a doubled haploid (DH) population derived from synthetic hexaploid wheat. We developed a linkage map consisting of 285 simple sequence repeat markers on the 21 chromosomes of common wheat based on a population of 186 DH lines. With this framework map, we identified 19 QTL associated with seed dormancy and/or sprouting rate of intact seeds on spikes, which were evaluated for the mapping population grown under the local environment conditions from 2006 to 2010. Several QTL expressed in multiple years during the research period and could be used to improve local cultivars for resistance to pre-harvest sprouting. (SD)

Clone and characterize qSD12, a major QTL for seed dormancy in rice. Five candidate genes in the narrowed qSD12 region were sequenced from donor and recipient parents of the dormancy QTL enhancing alleles and sequences annotated. More than 20 new markers were developed based on polymorphism between genomic DNA sequences from the two parents and the markers are been using to conduct a haplotype analysis for about 200 cultivars to understand the origin, differentiation and distribution of the major dormancy gene. Three of the five candidates have been transformed into a non-dormant cultivar to confirm their dormancy functions by complementation. Development of transgenic rice and transgenic plant analysis are under way. (SD)

Identify downstream gene networks regulated by SD7-1, a seed dormancy gene cloned from weedy rice. SD7-1 was map-based cloned as the red pericarp color gene Rc in weedy red rice and is annotated as a bHLH family transcription factor. Both microarray and yeast-two-hybridization (Y2H) analyses were used to identify gene networks regulating the seed dormancy and pigment traits and partners of the transcription factor. Three genes for biosynthesis of abscisic acid (ABA, a dormancy-inducing hormone) and nine genes in a conserved flavonoid biosynthetic pathway were up-regulated by SD7-1. Higher ABA content was detected in the dormant than in the non-dormant isogenic lines of SD7-1. Histological analysis demonstrated that the flavonoid pigment expresses only in the lower epidermal cell layer of the pericarp tissue. Y2H analysis is under way.(SD)

Develop isogenic lines for additional seed dormancy QTL. Seed dormancy QTL qSD1-1, 1-2, 4, and 7-2 loci were finely mapped onto the genomic region of <100 kilo base pairs and the dormancy-enhancing alleles introduced into the same genetic background to facilitate cloning and molecular characterization of the QTL underlying genes. (SD)

Since our last report, we have focused on improving wheat quality through changes in the expression of genes for thioredoxin (Trx) - regulatory protein functional through biology. The results suggest that by changing the levels of this key protein, wheat can be improved in two fundamental parameters: allergenicity and preharvest sprouting. The work has been published in comprehensive papers, coauthored with U.S. and Chinese collaborators. (CA, Berkeley)

Work with cereals (barley and wheat) and a legume (Medicago truncatula) has established extraplastidic Trx h as a central regulatory protein of seeds. Trx h acts by reducing disulfide (S-S) groups of diverse seed proteins (storage proteins, enzymes and enzyme inhibitors) thereby facilitating germination. Early in vitro protein studies using addition of components of the Trx system were complemented with experiments in which barley seeds with Trx h overexpressed in the endosperm showed accelerated germination and early or enhanced expression of associated enzymes (alpha-amylase and pullulanase). The current study extends the transgenic work to wheat. In the present study, [1], two approaches were followed to alter the expression of the Trx h genes in the endosperm: (1) a hordein promoter and its protein body targeting sequence led to overexpression of Trx h5, and (2) an antisense construct of Trx h9 resulted in cytosolic underexpression of that gene (Arabidopsis designation). Underexpression of Trx h9 led to effects opposite to those observed for overexpression Trx h5 in barley - retardation of germination and delayed or reduced expression of associated enzymes. Similar enzyme changes were observed in developing seeds. The lines with under expressed Trx showed delayed preharvest sprouting when grown in the greenhouse or field without a decrease in final yield. Wheat with overexpressed Trx h5 showed changes commensurate with earlier in vitro work: increased solubility of disulfide proteins and lower allergenicity of the gliadin fraction. The results are further evidence that the level of Trx h in cereal endosperm determines fundamental properties as well as potential applications of the seed. (CA - Berkeley)

In a more recent study [2], we obtained evidence that Trx h9, which was found to be bound to the plasma membrane, acts in a manner not previously seen for a Trx-i.e., it can move from cell-to-cell. Analysis of Trx h9 revealed a 17-amino acid N-terminal extension in which the second Gly (Gly2) and fourth cysteine (Cys4) were highly conserved. Mutagenesis experiments demonstrated that Gly2 was required for membrane binding, possibly via myristolation. Both Gly2 and Cys4 were needed for movement, the latter seemingly for protein structure and palmitoylation. A three-dimensional model was consistent with these predictions as well as with earlier evidence showing that a poplar ortholog of Trx h9 is reduced by a glutaredoxin rather than NADP-thioredoxin reductase, the reducing partner of other Trx's. In demonstrating the membrane location and intercellular mobility of Trx h9, the present results extend the known boundaries of Trx and suggest a role of Trx h9 in cell-to-cell communication. This work, which we plan to follow up with wheat, gives a new perspective to redox regulation and its role in seed development and germination. (CA - Berkeley)

Sugar beet is tolerant of high salinity, except during germination and stand establishment. Selection for improved germination in saline solutions was accomplished. Seed from one of these selections, EL-A022799 derived from Ames 3051, was evaluated using LC/MS/MS during germination in order to examine the presence and prevalence of small molecules implicated in salt tolerance in other species. Seedlings germinated in 0, 75, or 150 mM NaCl were evaluated for levels of glycine betaine, proline betaine, betaine aldehyde, choline, proline, sarcosine, and azetidine-2-carboxylic acid. Proline betaine was found at low levels in seedlings germinated in water, but the concentration of this compound decreased to barely detectable in salt germinated seedlings. Glycine betaine was abundant in the salt-selected Ames 3051 germinated in water, and was barely detectable in the non-salt tolerant control in the same conditions (and which did not germinate in NaCl). Interestingly, the glycine betaine level in salt-selected Ames 3051 decreased in response to increasing salt content in the germination medium until it reached a level similar to the control at zero salt, after which germination was not effective. (MI)

A candidate gene transcript profiling was untaken to examine early growth stages during germination. Genes involved in stress responses, signaling, and growth were activated within one hour after imbibition. Gene expression patterns were remarkable dissimilar between two contrasting legacy hybrids over the first 24 hours of germination. Fruit and true seed water uptake was measured in water and in hydrogen peroxide, with the result that hydrogen peroxide, which stimulates germination, does not appreciably affect fruit characteristics but rather acts on the true seed. Candidate genes demonstrated the involvement of a number of biochemical processes in the expression of seedling vigor, and some of these are still evident in contributing vigor in three-week old seedlings. (MI)

Tomato GeneChip analysis was performed to identify tissue-specific genes in tomato seeds. Tomato seeds were imbibed for 18 h and then dissected into the micropylar part and the rest of seed (termed as 'lateral' part). The embryonic tissues were removed from the micropylar and lateral parts, which were named endosperm cap (EC) and lateral endosperm (LE), respectively. Although both parts still contained testa (seed coat), the term endosperm was used because the testa is non-viable tissue in the mature tomato seed and does not affect expression analysis, an objective of which was to compare endosperm- and embryo-specific gene expression. The embryo was also divided into radicle- and cotyledon halves, which were named radicle-half embryo (R) and cotyledon-half embryo (C), respectively. RNA extracted from these four tissues was used for GeneChip analysis. EC-specific genes were identified, which included cell wall-associated genes, pathogenesis-related (PR) genes, and hormone metabolisms genes. (OR)

Analysis of the promoter regions of the EC-specific PR genes indicated that ethylene response factors might be the upstream regulators of the EC-specific genes. Consistently, tomato ETHYLENE RESPONSE FACTOR 1 (TERF1) was detected as one of the EC-specific genes. Bioinformatic analysis indicated that the promoter regions of the cell wall-associated genes, such as mannanase and expansins, also contained DNA motifs that are recognized by ethylene response factors. These results opened the possibility that ethylene response factors are the major upstream regulators of many genes specifically induced in the endosperm cap of tomato seeds. (OR)

Hormone Metabolism in Seeds. Genes encoding hormone metabolism enzymes that are important for seed dormancy and germination, such as abscisic acid (ABA) and gibberellin (GA) biosynthesis and deactivation enzymes, have been isolated. These genes are though to be controlled mainly at the level of transcription. A single transcriptional change in any of these genes could alter hormone levels in seeds and seed performance in terms of germination and dormancy. To enable manipulation of these rate-limiting enzymes, Plant Gene Switch System, an inducible gene expression system has been applied. Induction of an ABA biosynthesis gene was able to increase ABA levels in seed significantly and caused near-complete suppression of germination, providing a proof of concept for hormone metabolism engineering for seeds. (OR)

Relationships were developed with seed producers in the emerging wildflower seed industry of the southeast US and restoration/conservation practitioners to identify key areas of seed biology research. This is evidenced by $180,336 in funded grants spanning 200912. Funded projects revolved around seed dormancy in pre-variety germplasm and its alleviation, germination phenology, genetic diversity among seed producing populations of keystone species, development of viability testing methods, soil seed bank formation, and cryopreservation of wild germplasm. (FL)

Muskmelon (Cucumis melo L.) is a warm-season, frost-sensitive crop that germinates poorly at low temperatures. Cold-sensitive cultivar Noy Yizre'el (NY) and cold-tolerant cultivar Persia 202 (P-202) were compared at 15 and 25 degree C to determine how seed coat anatomy and oxygen uptake affected low-temperature germinability. The seed coats of both cultivars restricted oxygen uptake but 'NY' had a lower rate of oxygen uptake compared to P-202 with or without the seed coat. The poor germination of NY at lower temperatures was related primarily to lower embryo oxygen uptake in addition to the seed coat restriction of oxygen uptake. (VA)

Switchgrass (Panicum virgatum L.) is used horticulturally as an ornamental and agronomically as an animal feedstock and a putative bio-energy crop. Genetic transformation, using somatic embryogenic (SE) callus derived from mature seeds, is one strategy for improving switchgrass traits. A superior switchgrass line, HR8, was developed in using recurrent tissue culture selection from cv. Alamo that has low dormancy and produces a high percentage of somatic embryos. Eighty two percent of HR8 seeds germinated after harvest comparing to 26.8% for unselected Alamo. HR8 seeds that germinated produced 84.9% SE callus. (VA)

Evaluated Lycium chinense, Chinese goji berry, production from plants developed from tissue culture protocol developed in collaboration with Institute for Advanced Learning and Research Danville, VA. (VA)

Basil is a popular herb but little is known about its base, ceiling and optimal germination temperatures. Characterized the germination performance of two basil seed lots at different temperatures. (VA) Thermogradient tables are used to generate a wide range of temperatures for seed testing on the surface of an aluminum plate. A new thermogradient design with a finned surface to maintain temperatures vertically was developed. (VA)

Objective 2. Determine and model the biotic and abiotic factors affecting seed germination, seedling emergence, and establishment of sustainable populations in natural and agro-ecological systems.

We are collaborating in a workgroup on 'Germination, Trait Coevolution, and Niche Limits in Changing Environments' sponsored by the National Evolutionary Synthesis Center (NESCent) at Duke University. Though this group, we are working with colleagues at the University of Arizona (Larry Venable) and at the Institute of Botany, Chinese Academy of Sciences (Zhenying Huang) to conduct hydrothermal time analyses of seed germination of 13 native or introduced species. Dr. Venable has over 25 years of data on germination of these species in response to seasonal changes in temperature and rainfall, and we are analyzing their hydrothermal time responses in relation to after-ripening to assess how changes in dormancy relate to their ecological fitness and demographic success. We are also providing input to other members of this group on incorporating hydrothermal time concepts into demographic population models attempting to model and predict behavior of seed populations under changing environmental conditions, dependent upon their phonological life histories. (CA - Davis)

Used phage display and biopanning to identify PROTEIN ISOASPARTYL METHYLTRANSFERASE (PIMT) targets in Arabidopsis. (KY)

Using phage display and biopanning to examine the Arabidopsis LEA protein, SEED MATURATION PROTEIN1 (SMP1), and the soybean homolog, GmPM28, for protein binding partners at high temperature. (KY)

Objective 3. Develop, evaluate, and transfer technologies to assess and improve seed and seedling quality, health, performance, utilization, and preservation.

Research at Ohio State Univ. by Vanessa Neumann Silva, USP-ESALQ (Brazil) studied the relationship between Portulaca grandiflora and Portulaca sp. (hybrid) seed morphology, germination and vigor. Five lots of Portulaca grandiflora and two lots of Portulaca sp. were analyzed by non-destructive x-ray testing and subsequent germination, accelerated aging and seedling computer analysis by the Seed Vigor Imaging System (SVIS®). We verified the frequency of occurrence of free space for each lot. Accelerated aging data and image analyses indexes were submitted to ANOVA and Tukey's test with 5% of probability. The P. grandiflora seeds had free space between the embryo and endosperm ranging from 0-4.5%, in relationship to the whole area of the seed, and more than 8-0% of these seeds had free space between 0-1.5% for all lots. For lots 2, 3 and 4 the increasing free space was directly proportional to reductions in germination. From accelerated aging test data and seedling image analysis, lots 2 and 3 were the most vigorous; however, in these lots the percentage of seeds with extended free space (1.5-4.5%) was similar to the other lots, which suggests that in this situation free space had no influence on seed vigor. For Portulaca sp. lot 6 had large amounts of free space (almost 10% in class 3), and had lower germination, lower SVIS vigor index values and seedling length, lower germination after accelerated aging, and lower indexes of vigor, growth and uniformity of growth after the 72h of accelerated aging in relationship to lot 7. (OH)

The respiratory activity of individual seeds during imbibition and germination is being assessed using the Q2 instrument from ASTEC Global. Initial seed respiration during imbibition and germination is being characterized in relation to seed vigor and the effects of temperature and water potential on germination. The effects of respiratory inhibitors are also being tested to identify the metabolic pathways underlying different components of the oxygen uptake patterns exhibited by imbibed and germinating seeds. (CA - Davis)

The effects of seed drying methods on seed longevity are being assessed. Seeds exhibit hysteresis in their moisture content/relative humidity relationships, or isotherms. Seeds that are drying have moisture contents associated with a desorption isotherm this is generally 0.5 to 1% higher in moisture content than seeds that are hydrating to the same equilibrium RH on their sorption isotherm. This difference in seed moisture content results in differences in seed longevity. Based on these results, simple modifications to seed drying procedures may be able to extend seed longevity in storage. (CA - Davis)

With funding from the USAID-funded Horticulture Cooperative Research Support Program (HortCRSP), we are demonstrating and disseminating desiccant drying bead technology for seed drying and storage by smallholder farmers in India and Nepal. Seed drying beads can dry seeds efficiently in hermetic containers, and can be regenerated by heat and reused indefinitely. This technology has considerable promise for improving seed quality in humid regions. (CA - Davis)

It was determined that for gamagrass applications that require an immediate, specific field population, purchasing decisions and planting rates should be based on Pure Actual Germination (PAG), calculated from seed lot purity and actual germination percentages rather than a Pure Live Seed (PLS) basis. (KY)

Abscisic acid (ABA) treatments (frequency, rates, and timing of application) were investigated to reduce drought stress in jalapeno cv. Colima and bell pepper cv. Excursion and in watermelon cv. SF 800 (seeded) and SS 5244 (seedless). ABA was also studied as a potential tool to reduce chilling stress in seeded cv. Stargazer and seedless cv. Majestic watermelons in both greenhouse and immediately after field transplanting. (TX)

We conducted a project to address the accuracy of seed health tests on P. stewartii in corn and found that all of the available PCR methods will cross-react with other species of Pantoea. In addition, several unidentified isolates of Pantoea spp. have been isolated from corn in several countries, and we are investigating the genetic relatedness of the unknown species with known species of Pantoea. Currently we cannot recommend the use of PCR-based tests for P. stewartii phytosanitary testing. (IA)

Soybean seedborne pathogens - We completed a project in 2011 investigating interactions between seedborne viruses (SMV and BPMV) and Phomopsis longicolla. We found that infection of soybean plants by BPMV increased the susceptibility of these plants to seed infection by P. longicolla, and this predisposition was not related to virus effects on plant developmental rates. SMV did not have a similar effect. When vectors of BPMV are active, controlling them can contribute to control of both BPMV and seed infection by P. longicolla. (IA)

Corn seedling pathogens and nematode interactions - We are studying the interactions between root-lesion nematodes and Fusarium verticillioides, Fusarium graminearum, Rhizoctonia solani, and Pythium ultimum. Seedling disease symptoms were enhanced when nematodes were present in combination with any of the fungi, but the strongest interactions occurred with F. verticillioides and R. solani. Seed treatment combinations, including several fungicides and a nematicide (abamectin), provided the best improvements in seedling root development and growth. (IA)

Several new projects on soybean seed storage and drying are underway, as well as studies on soybean epigenetics and seed quality. Preliminary results on seed storage showed a poor relationship between excessive soil nutrients availability during plant growth and seed survival in storage. However, excess nutrients can be detrimental to seed quality. Seed priming can enhance epigenetic changes in the agronomic performance of the plant. (IA)

Work on mapping QTLs for germination of maize under low temperatures continues. We are investigating whether QTLs are expressed differently based upon the temperature of the stress conditions, and we have another study planned for this fall. (IA)

A flow meter was developed to measure the flow continuously and in real time for seed operations. A prototype was built and installed in a seed plant in Williams, Iowa. The data collected from Remington Seeds' Williams plant was analyzed and both electrical and mechanic vibration noise was observed. Modification of load cell mounting and electric isolation solved the problems. The prototype then was installed in the foundation seed plant of the CAD (Committee for Agricultural Development) in Ames for further testing. The flowmeter data at CAD was collected and analyzed. The plant manager reported that the flowmeter produces much less dust and is quieter. No left-over seeds were found inside the flowmeter and no abnormal wearing was observed on both the sensing unit and rubber boots. Test results indicated high corrections (r2=0.9909, 0.9903, and 0.9719 respectively for Large Flat corn, small round corn, and soybeans) between the measure weights and PLC readings. (IA)

Taylor's lab has state-of-the art seed coating technology using rotary pan technology, and he is a cooperator with pest management specialists at and outside Cornell. New chemistry seed treatments were applied to vegetable crops for control of insects or diseases. (NY)

Switchgrass (Panicum virgatum) is being explored as a biofuel crop, and weed management is a major production problem during the first year. Our approach was to apply an herbicide safener as a seed treatment to protect of the seed and seedlings from potential phytotoxicity from a chemical herbicide. (NY)

Bacteria Fruit Blotch (BFB) is a seed transmitted disease of cucurbits caused by Acidovorax avenae subsp citrulli (Aac) that is one of the most devastating diseases that affects both watermelon (Citrullus lanatus) and cantaloupe (Cucumis melo) production worldwide. Characterization of Aac strains revealed the existence of at least two well-differentiated groups of the disease. The first group includes strains that were mainly isolated from cantaloupe and pumpkin. While the second group represents the typical BFB strains that affect watermelon. The genome of Aac strain AAC00-1 (group II) was sequenced. Annotation of Aac genome revealed the existence of eleven putative type III effector genes including an avrRxo1 homolog. We cloned all known type III effectors from both group I and group II Aac strains and transiently expressed the effectors in a collection of cucurbit germplasm and Nicotiana benthamiana plants by using a Agrobacterium-mediated transient assays. The screening led to the identification of cucurbit germplasm that responds to the expression of Aac type III effectors. We plan to screen more cucurbit germplasm for resistance to specific effects, characterize the interplay of different type III effectors, and test which effectors have significant virulent contribution of Aac. (VA)

Recent human disease outbreaks of bacterial pathogens transmitted on vegetables, especially fresh spinach, have raised questions about the potential for seed transmission of human pathogens. The bacterial populations of spinach seed and seedling leaves were compared using DGGE, to assess bacterial community richness, and real-time PCR to compare the abundance of select phyla (total bacteria, Actinobacteria, Bacteroidetes, Firmicutes, a-Proteobacteria and b- Proteobacteria). To determine the effect of environment, the plants were grown in field and growth chambers. Vertical transmission of bacterial community members was evident because the developmental stage of the plant affected the richness and abundance of select bacterial phyla. The bacterial richness of plants grown in the two environments was not affected. However, a greater number of bacteria were associated with field grown samples in comparison to those produced in growth chambers. A statistically significant interaction existed between growth stage and environment for each of the selected phyla. Populations on cotyledons were smaller than mature leaves, but were not significantly different than the 3-4 leaf stage seedlings. The culturable populations of bacteria on seeds (~5 log CFU/g) were significantly smaller than determined using real time PCR (~7 log copies). Vertical transmission of bacteria from seeds to seedlings, suggests that bacteria may have evolved to ensure the transmission of certain bacteria. (VA)

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Journal of Experimental Botany, 61: 2229-2234. McDonald, M.R., K. Vander Kooi and A. Taylor. 2010. Comparison of various insecticide seed treatments and foliar sprays for control of damage by carrot rust fly and carrot weevil in carrots. Agriculture and Agri-Food Canada, 2009 PMR Report # 03. http://www.cps-scp.ca/pest_mangement-reports.shtml McDonald, M.R., K. Vander Kooi and A. Taylor. 2010. Evaluation of various seed treatments for control of onion smut in yellow cooking onions. Agriculture and Agri-Food Canada, 2009 PMR Report # 31. http://www.cps-scp.ca/pest_mangement-reports.shtml McGrath, J.M. (2011) Assisted breeding in sugar beets. Sugar Tech DOI 10.1007/s12355-010-0051-3 McGrath, J.M. (2011) Registration of EL54 and EL55 sugarbeet germplasms. Journal of Plant Registrations 5: 1 6. McGrath, J.M. (2011) Release of SR98/2 sugarbeet germplasm with high levels of resistance to Rhizoctonia damping-off. USDA-ARS Germplasm Release. 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