Pod indehiscence is a domestication and aridity resilience trait in common bean.

Plant domestication has strongly modified crop morphology and development. Nevertheless, many crops continue to display atavistic characteristics that were advantageous to their wild ancestors but are deleterious under cultivation, such as pod dehiscence (PD). Here, we provide the first comprehensive assessment of the inheritance of PD in the common bean (Phaseolus vulgaris), a major domesticated grain legume. Using three methods to evaluate the PD phenotype, we identified multiple, unlinked genetic regions controlling PD in a biparental population and two diversity panels. Subsequently, we assessed patterns of orthology among these loci and those controlling the trait in other species. Our results show that different genes were selected in each domestication and ecogeographic race. A chromosome Pv03 dirigent-like gene, involved in lignin biosynthesis, showed a base-pair substitution that is associated with decreased PD. This haplotype may underlie the expansion of Mesoamerican domesticates into northern Mexico, where arid conditions promote PD. The rise in frequency of the decreased-PD haplotype may be a consequence of the markedly different fitness landscape imposed by domestication. Environmental dependency and genetic redundancy can explain the maintenance of atavistic traits under domestication

Применение метода контрольных возмущений для определения характерных узлов присоединения комплексной нагрузки при расчетах динамической устойчивости

Рассматривается влияние способа замещения комплексной нагрузки на характер электромеханических переходных процессов в электрических системах (ЭС) от действия больших возмущений. Показано, что установить общие рекомендации относительно способа замещения нагрузки в сложных ЭС затруднительно. Предлагается для опреде­ления характерных узлов нагрузки, оказывающих существенное влияние на характер динамического перехода, применять известный метод контрольных возмущений. Приводятся результаты сравнительных расчетов с использованием предлагаемой методики

Is the USDA core collection of common bean representative of genetic diversity of the species, as assessed by SNP diversity?

Core collections are envisioned to be a representative subset of larger germplasm collections. They were introduced to facilitate the characterization and use of these germplasm collections. The common bean (Phaseolus vulgaris L.) core collection of the USDA Western Regional Plant Introduction Station was one of the first collections to be established in the early 1990s. Here, we evaluate the representativity of this common bean collection in light of the availability of a single nucleotide polymorphism (SNP) platform and new information about genetic diversity of the species, including phaseolin and seed type data. The SNP diversity was studied with a combination of STRUCTURE, principal coordinate analysis (PCoA), and neighbor-joining analysis (NJA). STRUCTURE analyses were conducted for K (number of subpopulations) = 3 and K = 7, based on the ad hoc statistic ΔK. The K = 3 analysis recognized the split between Andean and Mesoamerican domesticates and the subdivision of the Mesoamerican domesticates into high- (Durango/Jalisco) and low-altitude (Mesoamerica) ecogeographic races. The K = 7 analysis further subdivided the Andean group identified for K = 3, as well as the high-altitude group from the Mesoamerican gene pool. It also identified smaller groups consisting of Mesoamerican wild beans. The PCoA and NJA confirmed the STRUCTURE results and highlighted the existence of presumed hybridization among groups. Our results suggest that this core collection should be updated by adding domesticated categories, developing a separate wild common bean core collection, and developing cores for specific purposes