Response of chickpea (Cicer arietinum L.) genotypes to high temperature under late sown condition.

Abstract

Abstract

Global warming and fluctuating cropping conditions pose significant threats to food security in developing nations. Increased temperatures during reproductive phases, such as flowering, podding, and grain filling, in chickpea cause severe yield loss due to flower dropping and poor seed set. The heat stress (>35⁰C) at flowering and podding results in drastic reduction in seed yield. It has been reported by researcher that with increase of per 1°C temperature there is loss of 53 kg yield (Karla et al. 2008). To overcome this issue, it is crucial to screen and identify heat stress tolerance chickpea lines that can be used in breeding programs. This study evaluated 113 elite chickpea genotypes, including release varieties, land races, exotic collection, and advance breeding lines, at the research farm of ICAR-IIPR, Kanpur, during Rabi 2019-20 and 2020-21 under timely and late sown cropping environments. Analysis of variance of heat tolerance indices varied significantly and exhibited that high temperature has a direct impact on seed yield, with a reduction in mean seed yield of all genotypes under high temperature stress condition compared to non-stress conditions.

The study analyzed the correlation between seed yield under non-stress and stress-sown conditions and heat tolerance indices. Results showed a significant correlation between seed yield under non-stress conditions and heat tolerance indices like YI, STI, MP, MRP, GMP, and TOL. However, there was no significant correlation with HIS, RSI, and PYR. Seed yield (YP and YS) was positively correlated with heat tolerance indices viz., YI (1.00), YSI (0.714**), STI (0.969**), MP (0.946**), MPR (0.965**) and GMP (0.963**) under both non stress and stress conditions but negatively correlated with TOL, HIS, RSI, and PYR. Selection based on these indices could enhance grain production under non-stress and stress conditions (Table 5).

Through the interpretation of the result of Heat stress tolerance indices, PCA, Biplot and Clustering analysis some genotypes viz., IPC17-129 (6.71 %), IPC18-131 (7.46 %), IPC17-143 (8.73 %), IPC16-136 (9.05%) and IPC17-351 (9.16) exhibited very less reduction % in seed yield under high temperature stress condition as compared to suitable heat tolerance (ICC1205, ICC7110, ICC15614 and JG14) and susceptible (DCP92-3) checks. So, these genotypes may be considered as suitable heat stress tolerance genotypes. It can be used for cultivation or it could be used as parent in breeding program for transferring heat stress tolerance gene to suitable agronomic background.

Key words: Chickpea, Heat stress, Seed yield, Heat tolerance indices, PCA, Bilot, Clustering