Optimum harvest maturity for Leymus chinensis seed.

Jixiang Lin,Yongcui Wang,Chunsheng Mu,Xiaoyu Li,Mingming Qi,Yingnan Wang,Chunxue Yang

doi:10.1242/bio.017780

Abstract

ABSTRACTTimely harvest is critical to achieve maximum seed viability and vigour in agricultural production. However, little information exists concerning how to reap the best quality seeds of Leymus chinensis, which is the dominant and most promising grass species in the Songnen Grassland of Northern China. The objective of this study was to investigate and evaluate possible quality indices of the seeds at different days after peak anthesis. Seed quality at different development stages was assessed by the colours of the seed and lemmas, seed weight, moisture content, electrical conductivity of seed leachate and germination indices. Two consecutive years of experimental results showed that the maximum seed quality was recorded at 39 days after peak anthesis. At this date, the colours of the seed and lemmas reached heavy brown and yellow, respectively. The seed weight was highest and the moisture content and the electrical conductivity of seed leachate were lowest. In addition, the seed also reached its maximum germination percentage and energy at this stage, determined using a standard germination test (SGT) and accelerated ageing test (AAT). Thus, Leymus chinensis can be harvested at 39 days after peak anthesis based on the changes in parameters. Colour identification can be used as an additional indicator to provide a more rapid and reliable measure of optimum seed maturity; approximately 10 days after the colour of the lemmas reached yellow and the colour of the seed reached heavy brown, the seed of this species was suitable for harvest.

Highlights

Leymus chinensis is a perennial species of Poaceae, distributed in the Eastern region of the Eurasian steppe zone, the Northern and Eastern parts of the People’s Republic of Mongolia, and the Northeast China Plain (Lin et al, 2011)
As a consequence of this, an increasing number of Leymus chinensis seeds are required by humans; low seed germination percentages induced by dormancy hinder to its use in the restoration of deteriorated grassland
We found that the seed weight of the two experimental years both reached a maximum at 33 days after peak anthesis (DAPA); according to the germination test data, the germination quality at this stage was not maximum, so the seed weight can not be used as an indicator of the ideal seed harvest time of this species

Summary

Introduction

Leymus chinensis is a perennial species of Poaceae, distributed in the Eastern region of the Eurasian steppe zone, the Northern and Eastern parts of the People’s Republic of Mongolia, and the Northeast China Plain (Lin et al, 2011). It is an important fodder grass that can provide high protein and carbohydrate for grazing livestock. This plant is highly tolerant of the drought and saline-alkaline conditions in Northeast China (Huang et al, 2002). A growing number of grasslands have been degraded due to overgrazing; Leymus chinensis is considered as one of the most important plant species for grassland improvement in Northeast China (Liu and Qi, 2004; Yang et al, 1995). For the Leymus chinensis seed, the effect of harvest time has yet to be determined

Objectives

Methods

Results