Agro-morphological characterization of diverse sorghum lines for pre-and post-flowering drought tolerance

Abstract

The impact of drought stress on sorghum yield does not only depend on the intensity and timing of drought, but as well on the developmental stage of the crop. One of the limitations in breeding for pre-and/or postflowering drought stress resistance in sorghum is the less availability of diverse genetic sources possessing drought tolerant agro-morphological or physiological traits that could be introgressed into elite sorghum lines. This research evaluate a diverse group of 54 introgressed, converted, and commonly used sorghum breeding lines for their tolerance to field drought stress imposed at the pre-flowering and post-anthesis developmental stages in 2015 and 2016 growing seasons. Agro-morphological characteristics such as panicle area, panicle width, and percent green leaf and yield-related characteristics such as total above ground dry biomass and dry panicle weight were identified as significant predictors of grain yield under water stress. The current research identifies other sources that could be use by breeding programs as donor lines for traits related to pre-and postflowering drought tolerance in sorghum. Following statistical distribution and Tukey-Krammer HSD connecting letter tests, lines JB39, SC191, and SC270 and RIL R.11269 were identified as plausible sources for pre-flowering drought tolerance, and JB14, JB15, JB19, JB22, JB24, JB25, JB26, and JB33 as sources for the staygreen trait. While the staygreen is a good selection tool for postflowering drought tolerance, identifying staygreen lines with minimal reductions in grain yield and with earlier flowering dates (JB14, JB22, JB24 and JB25 in this study) than most commonly used staygreen donor lines, will ensure that grain yield is not over sacrificed by the ability of the crop to staygreen under terminal drought conditions.

Seed-to-seed early-season cold resiliency in sorghum

“…on yield will depend on the intensity, duration, and developmental stage of the crop. Stress, such as drought, at the reproductive stage in sorghum is usually characterized by drastic reduction in grain yields 19 , 20 . Other stages in sorghum sensitive to abiotic stress includes panicle initiation which occurs during the mid-developmental stage (GSII).…”

Assessment of agro-morphological variability of dry-season sorghum cultivars in Chad as novel sources of drought tolerance

“…According to 17 drought stress is a serious agronomic problem contributing to severe yield losses worldwide. This is not the case for the dry- season sorghum The staygreen trait gives plants the ability to retain greenness during grain ripening under water limited conditions 18,19 and this trait has been associated to drought tolerance 20,21 . Due to their ability to grown only under residual moisture soil, dry-season sorghum has a high resistance to drought 22 .…”

Composition, functional components, and physical characteristics of grain from staygreen and senescent sorghum lines grown under variable water availability

“…Grains from 23 of 55 grain sorghum lines (Supporting Information Table ; see Emendack, Burke, Laza, Sanchez, & Hayes, ) subjected to full irrigation and preflowering and postflowering water stress in the 2015 and 2016 growing seasons in the Amarillo fine sandy loam soil of Lubbock, Texas, were analyzed for nutritional composition. The 55 lines were selected either for their known staygreen (postflowering trait), senescence, or dhurrin levels determined from mature leaves of plants in the late vegetative stage.…”

“…The twenty‐three lines analyzed for grain composition and functional components (total protein % on dry basis, total starch percent on dry basis, total kafirin, percent kafirin protein, protein digestibility, and fermentation efficiency) and grain physical characteristics (average kernel hardness, average kernel weight, and average kernel diameter) were selected based on their 2015 field staygreen ratings using percent green leaf (number of green leaves as a percent of total number of leaves) 10 days to physiological maturity (Table , see Emendack et al., ). BTx642 was used as the staygreen check and SC1506 as the senescent check.…”