Grain filling of early-season rice cultivars grown under mechanical transplanting.

Jiana Chen,Min Huang,Fangbo Cao,Xiaohong Yin,Shuanglü Shan,Yingbin Zou,Jian Liu

doi:10.1371/journal.pone.0224935

Abstract

High yields of mechanized intensive rice-based cropping systems, e.g. double-season cropping using early- and late-season rice, are important to ensure national food security in China. However, few studies addressing the relationship between grain weight and grain yield of early-season rice under machine-transplanted conditions. A field experiment was conducted to determine the critical grain-filling characteristics and related physiological aspects that contribute to high grain weight in machine-transplanted early-season rice. The results showed that grain yield was significantly positively correlated with grain weight but not with panicles per m2, spikelets per panicle, and spikelet-filling percentage. Furthermore, this study demonstrated that there was a significant positive correlation between grain weight and mean grain-filling rate, which was significantly positively correlated with harvest index and grain cytokinin content. These results indicate that high grain-filling rate driven by good transport of assimilates to grains and strong grain sink strength is responsible for high grain weight in machine-transplanted early-season rice.

Highlights

Rice is the staple food for more than 65% of the population in China
In order to ensure national food security, intensive rice-based cropping systems have been extensively developed in China [1]
Hongthong et al [13] compared grain yield between two super hybrid cultivars differing in grain weight, and the results indicated that developing rice cultivars with high grain weight is a possible approach to achieve high grain yield

Summary

Introduction

In order to ensure national food security, intensive rice-based cropping systems have been extensively developed in China [1]. Double-season cropping using early- and late-season rice is a major intensive rice-based system in China [2]. The planting area of doubleseason rice has sharply decreased from 19.3 million ha in 1985 to 11.8 million ha in 2016 in China [5]. To overcome this situation, several simplified cultivation technologies have been developed for rice production in China [6] and large-scale farming has been used to utilize labor effectively. The development of large-scale farming has promoted the adoption of machine-transplanting technologies for rice production in China [9]

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Methods

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Discussion

Conclusion