摘要
改良株型结构是挖掘玉米产区光、热、水潜力的重要途径,是玉米理想株型育种的基础。为了深入揭示玉米株型相关耐旱响应机理,研究在花期干旱胁迫下对株型差异较大的3份玉米基因型(廊黄、昌7-2和TS141)穗位叶的株型结构、气孔形态、生理代谢、光合特性及产量进行了研究。结果表明:1)干旱胁迫下,3份不同株型基因型的叶长、叶宽、叶面积及叶夹角均显著减少,叶形系数和叶向值均显著增大,平展株型基因型TS141的6个株型性状较紧凑株型基因型廊黄和昌7-2变化更大;2)干旱导致3份不同株型基因型的上/下表皮气孔个数趋于增多,上/下表皮气孔长度和宽度趋于缩短,TS141的上/下表皮气孔个数均有较大的增多,上/下表皮气孔长度和宽度均有较小的降低;3)干旱胁迫后,TS141的叶绿素a、b、(a+b)含量及叶绿素a/b均明显下降,廊黄和昌7-2的叶绿素a/b均有较小地上升,其余3个性状均有较小地下降;4)干旱条件下,3份不同株型基因型的气孔导度、净光合速率、叶片温度、蒸腾速率和RuBPCase活性均有不同程度地减少,胞间CO2浓度均有不同程度地升高,与TS141相比,廊黄和昌7-2变化的幅度更小;5)干旱处理后,3份不同株型基因型的单株产量、单穗重、穗粒重、百粒重、穗长及出籽率均显著下降,对TS141的影响程度远大于廊黄和昌7-2;6)主成分PCA分析和热图Hierarchical clustering分析表明,干旱胁迫下玉米这些性状间的关系较为复杂,彼此相互关联,这些性状能完全概括不同株型基因型的耐旱性差异。因此,推测玉米株型结构作为重要的干旱调节者,其可与气孔形态、生理代谢及光合特性相互调节共同构成玉米株型相关耐旱响应机制,且由于紧凑株型玉米对干旱胁迫的调节能力更强,其在今后育种中具有更好的抗旱潜能。
Improvement of plant architecture is an important way to fully exploit the potential of environmental resources of light,heat,and water in maize(Zea mays)production,and it is the basis of breeding targeting ideal plant type.This research studied the response mechanisms of drought tolerance related to plant architecture in maize.The plant architecture traits,stomatal morphologies,physiological metabolisms and photosynthesis characteristics of ear leaf,and yield were recorded for three different maize genotypes(Langhuang,Chang7-2,and TS141)with differing plant architecture under drought stress during the flowering stage.It was found that:1)Leaf length,leaf width,leaf size,and leaf angle were decreased significantly,and leaf shape value and leaf orientation value of the three maize genotypes were increased significantly under drought stress.Moreover,genotype TS141,characterized as‘flat’,had larger changes of these six plant architecture traits than genotypes characterized as‘compact’(Langhuang and Chang 7-2);2)Drought stress increased the numbers of upper and lower epidermal stomata of all three maize genotypes,but decreased stomatal length and width.The change in stomatal number of TS141 was greater than for the other cultivars,and the size reduction was smaller;3)Chlorophyll a,b,and(a+b)contents,and chlorophyll a:b ratio of TS141 were significantly decreased by drought.For the tested genotypes,chlorophyll a:b ratio had a smaller increase,and the other three traits had a smaller decrease in Langhuang and Chang 7-2 after drought stress than in TS141;4)Stomatal conductance,net photosynthetic rate,the temperature of leaf thermocouples,transpiration rate,and RuBPCase activity decreased to different degrees in different genotypes,and intercellular CO2 concentration increased to different degrees in the three tested maize genotypes under drought stress.However,compared with TS141,Langhuang and Chang 7-2 had smaller changes;5)Yield per plant,ear weight,grain weight,1000-seed weight,ear length,and kernel ratio of all three maize genotypes were decreased significantly under drought stress,and TS141 was affected more severely than Langhuang and Chang 7-2;6)Principal component analysis and a heat map with hierarchical cluster analysis indicated that the relationships among these traits in maize under drought stress were complex and interrelated with each other,and could completely account for the differences in drought tolerance between the different plant architecture genotypes.Therefore,it is deduced from these results that plant architecture may be an important drought regulator that can be co-regulated with stomatal morphologies,physiological metabolisms,and photosynthetic characteristics to form the response mechanisms of drought tolerance.Moreover,because'compact'maize genotypes displayed stronger drought tolerance,these types have better drought tolerance potential for use in future breeding work.
作者
赵小强
陆晏天
白明兴
徐明霞
彭云玲
丁永福
庄泽龙
陈奋奇
张大志
ZHAO Xiao-qiang;LU Yan-tian;BAI Ming-xing;XU Ming-xia;PENG Yun-ling;DING Yong-fu;ZHUANG Ze-long;CHEN Fen-qi;ZHANG Da-zhi(Gansu Provincial Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China;Huangyang, Gansu Academy of Agricultural Sciences Proving Ground, Wuwei 733000, China)
出处
《草业学报》
CSCD
北大核心
2020年第2期149-162,共14页
Acta Prataculturae Sinica
基金
甘肃农业大学科技创新基金-公招博士科研启动基金(GAU-KYQD-2018-19)
甘肃农业大学甘肃省干旱生境作物学重点实验室开放基金(GSCS-2019-8)
甘肃省高等学校创新能力提升项目(2019A-052)
国家重点研发计划(2018YFD0100203-4)
甘肃省重点研发计划项目(18YF1NA071)
甘肃省重大科技专项(17ZD2NA016)
中科院“西部之光”项目(20180504)
甘肃省自然科学基金(18JR3RA189)
兰州市科技计划项目(2018-1-103)资助
关键词
玉米
株型结构
干旱胁迫
气孔形态
叶绿素
光合特性
产量
maize
plant architecture
drought stress
stomatal morphology
chlorophyll
photosynthetic characteristics
yield
