RESUMEN
Chickpea (Cicer arietinum) is among the founder crops domesticated in the Fertile Crescent. One of two major forms of chickpea, the so-called kabuli type, has white flowers and light-colored seed coats, properties not known to exist in the wild progenitor. The origin of the kabuli form has been enigmatic. We genotyped a collection of wild and cultivated chickpea genotypes with 538 single nucleotide polymorphisms (SNPs) and examined patterns of molecular diversity relative to geographical sources and market types. In addition, we examined sequence and expression variation in candidate anthocyanin biosynthetic pathway genes. A reduction in genetic diversity and extensive genetic admixture distinguish cultivated chickpea from its wild progenitor species. Among germplasm, the kabuli form is polyphyletic. We identified a basic helix-loop-helix (bHLH) transcription factor at chickpea's B locus that conditions flower and seed colors, orthologous to Mendel's A gene of garden pea, whose loss of function is associated invariantly with the kabuli type of chickpea. From the polyphyletic distribution of the kabuli form in germplasm, an absence of nested variation within the bHLH gene and invariant association of loss of function of bHLH among the kabuli type, we conclude that the kabuli form arose multiple times during the phase of phenotypic diversification after initial domestication of cultivated chickpea.
Asunto(s)
Alelos , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética , Cicer/genética , Domesticación , Variación Genética , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/metabolismo , Cicer/anatomía & histología , Productos Agrícolas/genética , Ecotipo , Flores/anatomía & histología , Flores/fisiología , Regulación de la Expresión Génica de las Plantas , Haplotipos/genética , Filogenia , Polimorfismo de Nucleótido Simple/genética , Análisis de Componente Principal , Semillas/anatomía & histologíaRESUMEN
Domesticated species are impacted in unintended ways during domestication and breeding. Changes in the nature and intensity of selection impart genetic drift, reduce diversity, and increase the frequency of deleterious alleles. Such outcomes constrain our ability to expand the cultivation of crops into environments that differ from those under which domestication occurred. We address this need in chickpea, an important pulse legume, by harnessing the diversity of wild crop relatives. We document an extreme domestication-related genetic bottleneck and decipher the genetic history of wild populations. We provide evidence of ancestral adaptations for seed coat color crypsis, estimate the impact of environment on genetic structure and trait values, and demonstrate variation between wild and cultivated accessions for agronomic properties. A resource of genotyped, association mapping progeny functionally links the wild and cultivated gene pools and is an essential resource chickpea for improvement, while our methods inform collection of other wild crop progenitor species.
Asunto(s)
Cicer/genética , Productos Agrícolas/genética , Agricultura , Cicer/clasificación , Cicer/fisiología , Ecología , Ambiente , Variación Genética , Genoma de Planta , Genómica , Genotipo , Semillas/clasificación , Semillas/genética , Semillas/fisiologíaRESUMEN
For children with moderate or severe cerebral palsy (CP), a foundational early goal is independent sitting. Sitting offers additional opportunities for object exploration, play and social engagement. The achievement of sitting coincides with important milestones in other developmental areas, such as social engagement with others, understanding of spatial relationships, and the use of both hands to explore objects. These milestones are essential skills necessary for play behavior. However, little is known about how sitting and play behavior might be affected by a physical therapy intervention in children with moderate or severe CP. Therefore, our overall purpose in this study was to determine if sitting skill could be advanced in children with moderate to severe CP using a perceptual motor intervention, and if play skills would change significantly as sitting advanced. Thirty children between the ages of 18 months and 6 years who were able to hold prop sitting for at least 10 s were recruited for this study. Outcome measures were the sitting subsection of the Gross Motor Function Measure (GMFM), and the Play Assessment of Children with Motor Impairment play assessment scale, which is a modified version of the Play in Early Childhood Evaluation System. Significant improvements in GMFM sitting scores (p < 0.001) and marginally significant improvement in play assessment scores (p = 0.067) were found from pre- to post-intervention. Sitting change explained a significant portion of the variance in play change for children over the age of 3 years, who were more severely affected by CP. The results of this study indicate that advances in sitting skill may be a factor in supporting improvements in functional play, along with age and severity of physical impairment.
RESUMEN
The use of assisted reproductive technology is increasing rapidly. Research, although sparse, has resulted in inconsistent findings as to the developmental prognosis for infants conceived by assisted reproductive techniques such as in vitro fertilization and the use of fertility drugs. In the present study, the authors compared twins who were spontaneously conceived with those who were conceived through assisted reproductive technology. The authors found differences in birth weight and gestational age. Infants conceived by assisted reproductive technology fared worse than did those who were spontaneously conceived. The authors found no differences between the groups in mental development at 24 months of age, but they found evidence of differences in physical development. Implications of the findings are discussed.