High Temperature Induced Glume Closure Resulted in Lower Fertility in Hybrid Rice Seed Production

Abstract

Predicted climate changes, in particular, the increased dimension and frequency of heat waves, are expected to affect crop growth in the future seriously. Hybrid rice relies on seed production from male sterile and restorer lines. Experiments were conducted over two consecutive years to compare the high temperature tolerance of parents of different hybrid rice combinations, in terms of fertility rate, flowering pattern, pollination and physiological parameters of the lodicule. Three male sterile lines and a broad compatibility restorer line (as pollen donor and conventional variety as well) were grown to heading stage and then treated with average daily temperatures of 26°C (range 23–30°C), 28°C (25–32°C), and 30°C (26–34°C), respectively, continued for 5–7 days each in a natural light phytotron which simulated the local typical high temperature weather in the field. The results indicated that male sterile lines were more sensitive to high temperature than the restorer line for fertility rate, and the sensitivity varied between varieties. The fertility rate of the restorer line was maintained at about 90% under the high temperature treatments, while it decreased in the male sterile lines by 23.3 and 48.1% at 28 and 30°C, respectively. The fertility rate of the most sensitive line declined by 70%, and the tolerant line declined by 34% at 30°C. Glume closure in the male sterile lines was a major reason for the reduced fertility rate under high temperature, which is closely correlated with carbohydrates content and the vascular bundle pattern in the lodicule. The present study identified a useful trait to select male sterile lines with high temperature tolerance for seed production.

Peer Review #2 of "iTRAQ-based quantitative proteome analysis reveals metabolic changes between a cleistogamous wheat mutant and its wild-type wheat counterpart (v0.2)"

“…Therefore, we infer that the WAS is a critical period for the lodicules. An overview of the pathways for proteome metabolic changes in lodicules Many substances regulate the osmotic pressure of lodicules, such as soluble sugar (Zee & O'Brien, 1971;Wang, Gu & Gao, 1991;Yan et al, 2017), starch (Pissarek, 1971), calcium (Qin, Yang & Zhao, 2005;Chen et al, 2016) and potassium (Heslop-Harrison & Heslop-Harrison, 1996;Chen et al, 2016;Liu et al, 2017). Our findings, together with those of previous studies, provide an overview of the metabolic pathways involving the carbohydrates that regulate the osmotic pressure of the lodicules.…”

High Nitrogen Levels Alleviate Yield Loss of Super Hybrid Rice Caused by High Temperatures During the Flowering Stage

“…Shorter grain filling durations caused by high temperatures were due to the loss of sink activity owing to earlier senescence of the panicle (Kim et al, 2011). Previous studies have indicated that an increase in spikelet sterility caused by high-temperature stress was caused by abnormal anther dehiscence (Matsui and Omasa, 2002), glume closure (Yan et al, 2017) and impaired pollination (Matsui et al, 2005) and pollen germination (Jagadish et al, 2009). In the Yangtze Valley, Tian et al (2009) observed that a maximum temperature of approximately 35°C or daily mean temperature of 30°C (with relative humidity of approximately 70% and low wind speeds) lasting for more than 3 days during the flowering period, led to significant seed-set losses in rice plants.…”

iTRAQ-Based Quantitative Proteomics Analysis on Rice Anther Responding to High Temperature

“…It is one of the major goals for rice breeder to develop HS resistant cultivar [ 15 , 16 ]. It has been suggested that rice resistance to HS is a quantitative trait [ 17 ].…”