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Effect of short term heat stress on grain filling in winter wheat
Abstract
The occurrence of hot days during the wheat (Triticum aestivum L.) grain filling period reduces wheat grain yield. Many genotypes never recover and finish kernel development after temperatures moderate. The objectives were to study the effect of short term heat stress during kernel development, to determine the effectiveness of a membrane thermostability test to predict wheat heat tolerance, and to study the effects on end-use quality. Wheat heads were treated during grain filling using heat chambers in a greenhouse with 12 h at 38$\sp\circ$, 12 h at 25$\sp\circ$C for a total of 96 hours. Leaf tissues of seedlings and plants during grain filling were heat treated for membrane thermostability at 48$\sp\circ$C for 1 h. For field trials, the heads were inserted to inverted glass flasks. The temperature differential between inside and outside the flasks was about 10-15$\sp\circ$C. Grain weight gains to maturity were different among genotypes following treatment. This significant genotype by heat treatment interaction indicated response to heat stress is under genetic control. Heat tolerance could be identified at the kernel level using heater boxes. However, the level of tolerance was small, indicating it might be difficult to breed for heat tolerance. Though the results were consistent within an environment, the results of membrane themostability test from seedlings versus hardened greenhouse plants and field plants did not agree. Genotypes responded differently to heat in each environment. The membrane thermostability test for heat tolerance should be used with caution as a predictor of heat tolerant wheat genotypes. The effect of heat stress treatment on the end-use quality was significant. There was significant genotype by treatment interaction for protein content and mixing tolerance mainly due to changes in magnitude. Hence, the effect of heat stress on the end-use quality is under both genetic and environmental control. The fluctuating heat treatment was similar to actual ambient temperature fluctuation. Comparisons could be made among genotypes with the same anthesis date or among genotypes with different anthesis dates if the ambient temperatures and solar radiation were similar.
Subject Area
Agronomy|Agriculture
Recommended Citation
Masrizal, "Effect of short term heat stress on grain filling in winter wheat" (1995). ETD collection for University of Nebraska-Lincoln. AAI9536621.
https://digitalcommons.unl.edu/dissertations/AAI9536621