Developing a Selection Criterion for Terminal Heat Tolerance in Bread Wheat Based on Various Mopho-Physiological Traits

To estimate the level of heat tolerance for different genotypes of bread wheat with respect to morphological characters under studied grains/ spike, grain weight/spike, grain filling duration (duration between the anthesis stage and the physiological maturity), 1000-kernel weight and grain yield/plant for yield. Physiological traits like relative injury (RI %), chlorophyll content, canopy temperature depression (CTD), were used in present investigation to contribute toward capability of plants to tolerate heat stress of the yield contributing traits during heat stress.The findings of present investigation had clearly explained that influences of environments on morpho physiological characters i.e. grain yield per plant (14886.15) and its attributing traits i.e. spike length (459.7), tillers per plant (622.34), spikelets per spike (278.1), 1000 kernel weight (13262.39), grain weight per spike (177.89) and number of grains per spike (2898.44) in wheat were highly significant and positive. Among the parent and their crosses had handsome amount of variations across the environment. The results of interaction for environments with parents, lines, testers and their crosses with respect to morpho physiological characters in wheat was found significant for some characters while variation was absent for other characters studied. Physiological traits like relative injury per cent, chlorophyll content and CTD were vital parameters to quantify the degree of heat stress to develop tolerant genotypes which is urgent and present need under changing climate scenario.

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Genetic dissection of physiological traits over trait based breeding in bread wheat conferring terminal heat tolerance

Cereal Research Communications ◽

10.1007/s42976-021-00139-z ◽

2021 ◽

Author(s):

Devender Sharma ◽

Jai Prakash Jaiswal ◽

Navin Chander Gahtyari ◽

Anjana Chauhan ◽

Narendra Kumar Singh

Keyword(s):

Bread Wheat ◽

Heat Tolerance ◽

Physiological Traits ◽

Genetic Dissection

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Evaluation of groundnut genotypes for heat tolerance under field conditions in a Sahelian environment using a simple physiological model for yield

The Journal of Agricultural Science ◽

10.1017/s0021859600008583 ◽

2001 ◽

Vol 136 (1) ◽

pp. 81-88 ◽

Cited By ~ 15

Author(s):

B.R. NTARE ◽

J.H. WILLIAMS ◽

F. DOUGBEDJI

Keyword(s):

Growth Rate ◽

Heat Tolerance ◽

Selection Criterion ◽

Crop Growth ◽

Field Conditions ◽

Physiological Traits ◽

Yield Model ◽

Crop Growth Rate ◽

Pod Yield ◽

Partitioning Coefficient

Heat tolerance of groundnut (Arachis hypogaea L.) was evaluated under field conditions using physiological traits identified in a yield model [crop growth rate (C), reproductive duration (Dr) and partitioning (p)]. In 1991, 625 diverse genotypes were initially screened under irrigation during the hottest months (February to May). Subsequent tests consisted of 16 contrasting genotypes selected based on a combination of high pod yield and partitioning coefficient of >0· 50. Large variation was observed among the 625 genotypes for pod yield and physiological traits. C was a powerful factor influencing pod yield. Eight genotypes combining high pod yield and a partitioning coefficient greater than 0·6 were identified. These included two released cultivars (55–437 and 796) in the Sahel. Correlations between seasons were significant for p (r=0·84), but non-significant for pod yield (r=0·40), C (r=0·39), and Dr (0·36). Date of sowing and genotypes had significant effects on pod yield and C, but were slight on p and Dr. Pod yield of most genotypes declined by more than 50% when flowering and pod formation occurred when maximum temperatures averaged 40°C. The results revealed that estimates of p would be a more reliable selection criterion for identification of genotypes tolerant to heat than yield. Further research is suggested to maximize crop growth rate and partitioning of genotypes growing under supra-optimal temperatures.

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