25 research outputs found
Association mapping for yield and grain quality traits in rice (Oryza sativa L.)
Association analysis was applied to a panel of accessions of Embrapa Rice Core Collection (ERiCC) with 86 SSR and field data from two experiments. A clear subdivision between lowland and upland accessions was apparent, thereby indicating the presence of population structure. Thirty-two accessions with admixed ancestry were identified through structure analysis, these being discarded from association analysis, thus leaving 210 accessions subdivided into two panels. The association of yield and grain-quality traits with SSR was undertaken with a mixed linear model, with markers and subpopulation as fixed factors, and kinship matrix as a random factor. Eight markers from the two appraised panels showed significant association with four different traits, although only one (RM190) maintained the marker-trait association across years and cultivation. The significant association detected between amylose content and RM190 was in agreement with previous QTL analyses in the literature. Herein, the feasibility of undertaking association analysis in conjunction with germplasm characterization was demonstrated, even when considering low marker density. The high linkage disequilibrium expected in rice lines and cultivars facilitates the detection of marker-trait associations for implementing marker assisted selection, and the mining of alleles related to important traits in germplasm
Chacras of the pukara: the late occupation (tenth-sixteenth centuries) of Mesada de Andalhuala Banda, Yocavil (Catamarca, Argentina)
This chapter presents the results of archaeological survey undertaken in the Mesada de Andalhuala Banda, Southeast Yocavil Valley, Catamarca, Northwest Argentina (NWA). Three hundred and eighty-two architectural units (AU) were registered, which suggests a prolonged occupation during the first and second millennia AD. In this opportunity, I will focus on the Late Period occupation tenth?sixteenth centuries) and the evidence reflecting activities of the agricultural production cycle, including structures for cultivation, mounds, and longitudinal accumulation of stones that were the product of land clearing, irrigation systems, milling tools, and circular storage structures. Spatially associated with these features are simple and compound residential units with double-faced walls filled with rubble and sediment, morphology assignable to the Santa María culture, which could be the dwelling sector of the population tasked with food production. This information allowed us to hypothesize that the Mesada, as a main productive area, was occupied during the entire Late Period, a time that included climate change and interethnic conflict, and played an important role in relation to the nearby pukara settlement.Fil: Alvarez Larrain, Alina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto de las Culturas. Universidad de Buenos Aires. Instituto de las Culturas; Argentina. Universidad Nacional Autónoma de México; Méxic