《植物生理学报》 2017, 53(2): 280-290

弱光胁迫影响甘蔗叶片内源激素的平衡和分蘖进程

丘立杭^1,2,3,*, 李强^4,*, 黄杏^1,2,3, 罗含敏^1,2,3, 陈荣发^1,2,3, 吴建明^1,2,3,**, 李杨瑞^1,3,**, 陈栋⁵

¹中国农业科学院甘蔗研究中心, 南宁530007; ²广西壮族自治区农业科学院甘蔗研究所, 南宁530007; ³农业部广西甘蔗生物技术与遗传改良重点实验室/广西甘蔗遗传改良重点实验室, 南宁530007; ⁴广东省湛江农垦科学研究所, 广东湛江524086; ⁵来宾市食品药品监督管理局来宾市食品药品检验检测中心, 广西来宾546100

通信作者：丘立杭；E-mail: wujianming2004@126.com; liyr@gxaas.net

摘　要：

光是甘蔗生长发育的重要环境因子, 充足的光照是甘蔗生育期中分蘖形成和生长的基础。然而, 广西特殊的地形地貌限制了蔗田的光照条件, 从而影响甘蔗分蘖及分蘖成茎和蔗茎产量。为揭示弱光胁迫对甘蔗分蘖生长发育及其内源激素含量的影响, 以生态适应性较好的甘蔗优良品种‘桂糖29号’为试验材料, 全自然光强为对照, 通过遮荫形成不同的弱光胁迫, 调查不同弱光胁迫下甘蔗分蘖及生长情况, 同时分析胁迫15、30、45、60 d时甘蔗叶片中叶绿素含量及生长素吲哚乙酸(IAA)、赤霉素(GA₃)、脱落酸(ABA)、玉米素核苷(ZR)含量的变化。结果表明: 弱光胁迫致使甘蔗分蘖生长发育明显延滞, 甘蔗分蘖发生时间至少滞后15 d, 严重的导致分蘖不发生和死亡; 甘蔗叶片叶绿素含量均显著升高, 但株高生长和茎径增粗均显著地受抑制, 进而导致植株生物量积累显著减少。进一步研究发现, 弱光胁迫下不同生育时期甘蔗叶片中内源激素含量大小为: ZR>IAA>ABA>GA₃。在适应弱光胁迫过程中, 甘蔗叶片的IAA、ABA和ZR含量均显著升高, IAA/ABA、IAA/ZR比值在分蘖适应寡照胁迫中表现为升高; GA₃含量和GA₃/ABA比值均先降后升; ZR含量和ZR/ABA比值表现为升高。这些内源激素含量和比例变化可能是甘蔗分蘖进程受到抑制的关键因素之一。

关键词：甘蔗; 分蘖; 弱光胁迫; 农艺性状; 内源激素

收稿：2016-10-08   修定：2017-02-15

资助：国家自然科学基金(31360312和31460102)、广西自然科学基金(2016GXNSFBA380034、2015GXNSFDA139011、2014GXNSFAA118128和2013GXNSFAA019073)、广西重点实验室建设项目(15-140-13)、广西科技计划项目(桂科攻1598006-1-2E)、广西八桂学者和特聘专家专项经费(2013)、国家农业产业技术体系广西甘蔗创新团队专项经费(gjnytxgxcxtd-03)和广西农业科学院项目(2015YM13和2015YT02)。

Weak-light stress caused by shading affects the balance of endogenous hormones in leaves and tillering process in sugarcane (Saccharum officinarum)

QIU Li-Hang^1,2,3,*, LI Qiang^4,*, HUANG Xing^1,2,3, LUO Han-Min^1,2,3, CHEN Rong-Fa^1,2,3, WU Jian-Ming^1,2,3,**, LI Yang-Rui^1,3,**, CHEN Dong⁵

¹Sugarcane Research Center, Chinese Academy of Agricultural Sciences, Nanning 530007, China; ²Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China; ³Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture, and Guangxi Key Laboratory of Sugarcane Genetic Improvement, Nanning 530007, China; ⁴Guangdong Zhanjiang Science Research Institute of Agricultural Reclamation, Zhanjiang, Guangdong 524086, China; ⁵Laibin Center for Food and Drug Control, Laibin, Guangxi 546100, China

Corresponding author: QIU Li-Hang; E-mail: wujianming2004@126.com; liyr@gxaas.net

Abstract:

Light is a very important environmental factor for the growth and development of sugarcane (Saccharum officinarum), including sugarcane tillering. Sufficient light during the growing period is the basis of tiller formation and growth in sugarcane. However, light conditions in sugarcane field are always limited by topography and geomorphology in Guangxi province, furtherly influence sugarcane tillering, millable stalks from available tillers and cane yield in production. To determine the effects of tillering formation and growth under weak-light environment in sugarcane, as well as endogenous hormone content, S. officinarum cv. ‘GT29’ seedlings were used to study the effects of different weak-light stresses on endogenous hormone contents in leaves and tillering process. The different weak-light stresses of 20.0%, 52.0% and 71.2% shading (respectively named as GS, GS1 and GS2) resulted from nylon nets (80.0% and 60.0% light transmittance) mulching from tillering stage to initial elongation stage. The results showed that the growth and development of sugarcane tillers were delayed under weak-light conditions, and the tillering process was postponed at least 15 days. The tillers did not produce or died during their growing under the weak light treatments (GS1 and GS2). The plant high, stalk diameter, fresh and dry weights of plants and tillering rate were significantly decreased while the total chlorophyll content was increased under different weak light conditions. Further study found that the content levels of hormones showed ZR>IAA>ABA>GA₃ in leaves. The contents of IAA, ABA and ZR and the ratios of IAA/ABA and IAA/ZR in leaves significantly increased while the GA₃ content and the GA₃/ABA ratio in leaves firstly decreased and then increased under weak-light stress at tillering stage. The changes in hormone contents and ratios may be one of key factors for inhibiting the process of tillering in sugarcane.

Key words: Saccharum officinarum; tillering; weak-light stress; agronomic trait; endogenous hormone