Effects of row direction and row spacing on maize leaf senescence.

Chang Tian,Yike Wang,Yangjie Lu,Yang Wang,Guo Zhen,Jichang Han,Juan Li,Yangyang Liu,Yuan Huang

doi:10.1371/journal.pone.0215330

Abstract

To analyze three row orientations (south-north, east-west, southwestern 20°) and two row spacings (‘65 + 65’, ‘160 + 40’), we investigated the effect of row orientation and planting pattern on photosynthetic performance, physiological and biochemical indicators related to the aging of leaves. Results revealed that during maturity stage, in north-south and east-west, the initial fluorescence (Fo) at ‘65 + 65’ were higher than those under‘160 + 40’; the maximum quantum yield of PS2 photochemistry(ΦP0), basal quantum yield of non-photochemical processes in PS2(ΦN0)of the lower leaves and photosynthetic rate of the upper and ear leaves under‘160 + 40’were higher than those under‘65 + 65’. The polyphenoloxidase (POD) activities of leaves at different positions under ‘160 + 40’ were higher than that under‘65 + 65’, while the malondialdehyde (MDA) content was lower. The photosynthesis rate, superoxide dismutase (SOD) and catalase (CAT) activity of leaves at different positions under southwestern 20° ‘160 + 40’ were higher than others. Whilst MDA content ‘160 + 40’ were lower. Therefore, in De Hui City, Jilin Province, southwestern 20° ‘160 + 40’ delayed leaf senescence at the late stage of growth of maize, as well as the effect of increasing maize yield was most obvious.

Highlights

Maize (Zea mays L.) has higher yields than rice and wheat
The effect of different planting patterns on Fo, FP0 and FN0 of leaves in different parts of maize was shown in Fig 6 and S2 Table
Our results showed that the photosynthetic rate of the ear leaf showed a downward trend after anthesis, indicating that photosynthesis decreased with leaf senescence

Summary

Introduction

Maize (Zea mays L.) has higher yields than rice and wheat. Maize has spread over China’s most area and become one of China’s major corps. To increase the production of maize, numerous experiments shave been done. Since 1988, Lu et al.[1] and Duan et al.[2] have proved that premature leaf function could largely affect the seed setting rate and further decide the grain yield; Later, Davide[3], Ma and Dwyer[4] demonstrated that premature leaf senescence, reduced green leaf area and shortened photosynthetic time would severely damage the grain yield. It’s well believed that keeping corps green and prolonging the photosynthetic time can improve the photosynthetic rate after anthesis, and significantly increase the grain yield.

Methods

Results

Discussion

Conclusion