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The genetic diversity of the USDA Lablab purpureus germplasm collection was assessed with polymorphic simple sequence repeat (SSR) markers derived from Medicago, soybean and cowpea. This assessment indicated that the USDA cultivated L. purpureus (L.) spp. purpureus collection was genetically limited and should be expanded. Phylogenetic analysis partitioned 47 representative accessions into two main clades, which had clearly diverged: a wild dade producing small seeds, and a cultivated dade producing large seeds. Wild dade accessions were easily resolved, whereas it was more difficult to distinguish among accessions in the cultivated dade. The sequence similarity to M. truncatula was variable from amplicon to amplicon. Sequence analysis of Lablab amplicons with the same SSR marker showed that the sequence content of these amplicons was almost identical, except for some single nucleotide polymorphisms (SNPs). This indicates that amplicons generated with SSR primers derived from Medicago, soybean and cowpea can be used as DNA markers to distinguish L. purpureus germplasm accessions at the DNA fragment level. Sequence analysis, as well as morphological characterisation, confirmed the SSR taxonomic classification. [ABSTRACT FROM AUTHOR]

Castor is an important oilseed crop and although its oil is inedible, it has multiple industrial and pharmaceutical applications. The entire US castor germplasm collection was previously screened for oil content and fatty acid composition, but its genetic diversity and population structure has not been determined. Based on the screening results of oil content, fatty acid composition, and country origins, 574 accessions were selected and genotyped with 22 polymorphic EST-SSR markers. The results from cluster analysis, population structure, and principal component analysis were consistent, and partitioned accessions into four subpopulations. Although there were certain levels of admixtures among groups, these clusters and subpopulations aligned with geographic origins. Both divergent and redundant accessions were identified in this study. The US castor germplasm collection encompasses a moderately high level of genetic diversity (pairwise dissimilarity coefficient = 0.53). The results obtained here will be useful for choosing accessions as parents to make crosses in breeding programs and prioritizing accessions for regeneration to improve germplasm management. A subset of 230 accessions was selected and will be planted in the field for establishing a core collection of the US castor germplasm. Further evaluation of the US castor germplasm collection is also discussed.

Background: Cryobanks are a secure, efficient and low cost method for the long-term conservation of plant genetic resources for theoretically centuries or millennia with minimal maintenance., Objective: The present manuscript describes CIP's modified protocol for potato cryopreservation, its large-scale application, and the establishment of quality and operational standards, which included a viability reassessment of material entering the cryobank., Materials and Methods: In 2013, CIP established stricter quality and operational standards under which 1,028 potato accessions were cryopreserved with an improved PVS2-droplet protocol. In 2014 the viability of 114 accessions cryopreserved in 2013 accessions were reassessed., Results: The average recovery rate (full plant recovery after LN exposure) of 1028 cryopreserved Solanum species ranged from 34 to 59%, and 70% of the processed accessions showed a minimum recovery rate of ≥20% and were considered as successfully cryopreserved., Conclusion: CIP has established a new high quality management system for cryobanking. Periodic viability reassessment, strict and clear recovery criteria and the monitoring of the percent of successful accessions meeting the criteria as well as contamination rates are metrics that need to be considered in cryobanks.

Cultivated peanut (Arachis hypogaea) is an allotetraploid with closely related subgenomes of a total size of ∼2.7 Gb. This makes the assembly of chromosomal pseudomolecules very challenging. As a foundation to understanding the genome of cultivated peanut, we report the genome sequences of its diploid ancestors (Arachis duranensis and Arachis ipaensis). We show that these genomes are similar to cultivated peanut's A and B subgenomes and use them to identify candidate disease resistance genes, to guide tetraploid transcript assemblies and to detect genetic exchange between cultivated peanut's subgenomes. On the basis of remarkably high DNA identity of the A. ipaensis genome and the B subgenome of cultivated peanut and biogeographic evidence, we conclude that A. ipaensis may be a direct descendant of the same population that contributed the B subgenome to cultivated peanut.

A study was designed to test the effect of animal source ammonia on some component concentrations in test atmospheres produced to measure the health effects of pollutants in the exhaust emissions of gasoline-powered engines equipped with oxidative catalyst converters. The dominantly acidic nature of the exhaust particulate phase required an evaluation of test chamber concentrations of the alkaline components contributed by the test animals. The animal population in the chamber was critical in maintaining the essential integrity of the pollutant atmosphere. Measures to minimize the production of the animal-produced interferent(s) were helpful in attenuating the interfering effect.