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United States Department of Agriculture

Agricultural Research Service

Research Project: IMPROVE GRAIN SORGHUM END-USE QUALITY & UTILIZATION BY IDENTIFYING THE PHYSICAL, CHEMICAL & ENVIRONMENTAL FACTORS RELATED TO FOOD & FEED...

Location: Grain Quality and Structure Research Unit

Title: Evaluation of sorghum [Sorghum bicolor (L.) Moench] lines and hybrids for cold tolerance under field and controlled environments

Authors
item Kapanigowda, Mohankumar -
item Perumal, Ramasamy -
item Aiken, Robert -
item Herald, Tom
item Bean, Scott
item Little, Christopher -

Submitted to: Canadian Journal of Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 22, 2013
Publication Date: September 3, 2013
Citation: Kapanigowda, M., Perumal, R., Aiken, R., Herald, T.J., Bean, S. and Little, C.R. 2013. Analyses of sorghum [Sorghum bicolor (L.) Moench] lines and hybrids in response to early-season planting and cool conditions. Canadian Journal of Plant Science. 93:773-784.

Interpretive Summary: Early season cold tolerance in sorghum contributes to emergence, seedling establishment, early vegetative growth, and reduces damping-off diseases under chilling conditions. The objectives of this study were to identify cold tolerant sources and to evaluate and optimize rapid screening techniques under a controlled environment. Forty-eight genotypes were selected and grown during 2011 in two locations. The results of the study showed that late emergence produces greater biomass compared to early emergence. A potting mixture study concluded that soil+vermiculate mix is more effective for controlled environment cold tolerance screening than soil+sand or soil+peat potting mixes.

Technical Abstract: Early season cold tolerance in sorghum contributes to emergence, seedling establishment, early vegetative growth, and reduces damping-off diseases under chilling conditions. The objectives of this study were to identify cold tolerant sources and to evaluate and optimize rapid screening techniques under a controlled environment. Field studies involving 48 genotypes including elite and advanced breeding lines, land races and hybrids while using commercial hybrids as checks were conducted with two planting dates on 02 May (early) and on 31 May (normal) in 2011 at two locations in Hays and Colby, Kansas. Significant differences among the genotypes were recorded for all the seedling traits (emergence percentage, emergence index (EI), shoot biomass, plant height and leaf number measured 30 days after emergence), agronomic traits (days to 50% flowering, panicle exertion, panicle length and plant height at maturity) and seed quality traits (kernel hardiness, kernel weight, kernel diameter, total phenolic and tannin content) traits. All 48 genotypes were also screened under greenhouse conditions for resistance to seedling disease caused by Pythium aphanidermatum and P. irregulare after inoculation under warm and cold temperature regimes. Eight advanced breeding lines (PI574578R/3/KS118B-3, PI574586R/4/KS119B-2, PI574578R/3/KS118B-4, PI574578R/3/KS118B-2, PI574570R/4/KS120B, PollenCompT4C4-210R/PI574554R-5, PollenCompT4C4-210R/PI574554R-3, TX430/SQR-2 and PI574599R/B35-6B) were selected for test hybrid evaluation to assess fertility status, combining ability and yield performance based on seedling (EI and biomass) and seed quality traits including low phenolic content with no tannins. Of these, PI574578R/3/KS118B-3, PI574586R/4/KS119B-2 and PI574570R/4/KS120B-2 showed tolerance to Pythium spp. infection. Significant correlation was observed between EI and biomass in both locations in early planting suggesting that late emergence produces greater biomass compared to early emergence. Screening in controlled environments (greenhouse and growth chamber -15/12 degrees Celsius day/night) was conducted at both locations in 2011 using 18 selected lines for EI and shoot biomass. Results indicated significant correlation between growth chamber and field study for EI and shoot biomass suggesting that the growth chamber provides a reliable preliminary cold tolerance assay for large breeding populations than reliance on field screening. A potting mixture study concluded that soil+vermiculate mix is more effective for controlled environment cold tolerance screening than soil+sand or soil+peat potting mixes.

Last Modified: 10/23/2014