Impact of low-temperature, overcast and rainy weather during the reproductive growth stage on lodging resistance of rice

Fei Weng,Wujun Zhang,Xia Xu,Zhenghui Liu,Shaohua Wang,Yanfeng Ding,Xiaoran Wu,Ganghua Li

doi:10.1038/srep46596

Fei Weng, Wujun Zhang + Show 6 more

Open Access

https://doi.org/10.1038/srep46596

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Abstract

The objectives of this study were to explore the mechanism by which the lodging resistance of the rice population during the late growth period responds to low-temperature, overcast and rainy weather during the reproductive growth stage. Field experiments were conducted using indica rice Yliangyou2 (lodging-resistance variety), IIyou084 (lodging-susceptible variety) and japonica rice Wuyunjing23 (lodging-resistance variety) and W3668 (lodging- susceptible variety) in 2013 (high temperature and strong radiation during the rice reproductive growth stage), 2012 and 2014 (low temperature and weak radiation during rice reproductive growth stage). The results showed that the length of the basal internodes and the height of the gravitational centres were greater in plants grown in 2014. Dry weight of basal culms, culm diameter, lignin content and total content of structural carbohydrates (lignin and cellulose) in basal internodes were reduced in these plants, causing a significant reduction in the bending stress and lodging resistance of the rice stems. Low-temperature, overcast and rainy weather had a greater effect on lodging resistance in indica rice compared with japonica rice. This was reflected in a greater reduction in the lignin content of the indica rice stems, which yielded a significantly lower breaking strength and bending stress.

Highlights

Promotes internode elongation and reduces culm wall thickness
A reduction in productive panicles resulted in fewer spikelets, the seed-setting rate and the 1000-grain weight both increased in the japonica rice varieties, which were likely the main reasons for the observed yield increases
The results showed that low-temperature, overcast and rainy weather could increase the risks of rice lodging and had a greater effect on indica varieties than on japonica varieties in terms of two stem strength parameters (BS and M)

Summary

Introduction

Promotes internode elongation and reduces culm wall thickness. This reduction results in fragile supporting tissue and low stem strength, aggravating lodging[16]. No study has systematically investigated how low-temperature, overcast and rainy weather affects the reproductive growth stage and rice stem strength and the associated differences between varieties. A rare period of long low-temperature, overcast and rainy weather was encountered during the reproductive growth stage of rice in East China in 2014. We conducted experiments related to lodging on two indica hybrid rice varieties and two japonica rice varieties under the same field management conditions. We analysed the differences in lodging resistance of rice stems from 2012 to 2014 in terms of physical properties, morphological characteristics, and chemical composition to provide a reference for research into lodging resistance in rice

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