摘要
为阐述拔节期弱光胁迫降低谷子产量的光合生理机制,以张杂谷5号和晋谷21号为研究对象,在拔节期分别进行30%、60%和85%的遮阴处理15 d,以不遮阴作为对照,探究谷子叶片的光合色素含量、光合特性、叶绿素荧光参数及产量对其的响应规律。结果表明,遮阴处理降低了2个品种谷子叶片的光合色素含量、净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、表观光合电子传递速率(ETR)、PSⅡ实际光化学量子产量(ΦPSⅡ)、光化学猝灭系数(q P)、非调节性能量耗散量子产量[Y(NO)]、穗长、穗重、穗粒重和产量,却显著提高了胞间CO2浓度(Ci)和调节性能量耗散量子产量[Y(NPQ)]。张杂谷5号的表观光合电子传递速率(ETR)、PSⅡ实际光化学量子产量(ΦPSⅡ)和产量在遮阴30%时显著下降,而晋谷21号在遮阴程度超过60%时才显著变化。总之,拔节期弱光胁迫下,谷子叶片的光合色素含量降低,捕捉利用光能的能力减弱,PSⅡ光化学活性降低,光合作用变弱,最终影响产量;张杂谷5号比晋谷21号对弱光胁迫更为敏感。本研究结果为拔节期通过改善谷子叶片的光合功能来增强抗弱光胁迫以达到稳产指明了方向,并为选育耐弱光胁迫谷子提供了依据。
To explore the mechanism of photosynthetic physiology of foxtail millet yield reduction caused under weak light stress at jointing-stage, two foxtail millet varieties, Zhangzagu 5 and Jingu 21, were subjected to different shading intensity treatments （0% , 30% , 60% and 85% ） at the jointing-stage for 15 days. The response of photosynthetic pigment contents, photosynthetic rate, and chlorophyll fluorescence parameters in the leaf and yield of the foxtail millet were investigated. The results showed that the shading treatment reduced the photosynthetic pigment contents, net photosynthetic rate （Pn）, transpiration rate （Tr）, stomatal conductance （Gs）, apparent photosynthetic electron transport rate （ ETR）, PSⅡ practical photochemical quantum yield （ dpPSⅡ ） , coefficient of photochemical quenching （qP） , and quantum yield dissipated by non-regulatory energy of the blade （Y （NO）） , ear length, ear weight, ear grain weight, and the yield of foxtail millet, but significantly improved intercellular CO2 concentration （Ci） , and the quantum yield Y（NPQ） dissipated by regulatory energy. ETR, dpPSⅡ , and the yield of Zhangzagu 5 significantly decreased upon 30% shading, but those of Jingu 21 greatly changed when the shading exceeded 60%. In conclusion, under weak- light stress at the jointing stage, the declined photosynthetic pigment contents, weakened capacity of catching and utilizing light energy, decreased PSII photochemical activity and declined photosynthetic rate cause the decreased yield of foxtail. Zhangzagu 5 is more sensitive to the low-light stress than Jingu 21. The results of this study point out a direction for enhancing the resistance to weak light to achieve stable production by improving the photosynthetic function of foxtail millet at jointing stage, and provide a basis for selective breeding of foxtail millet with weak light stress tolerance.
出处
《核农学报》
CAS
CSCD
北大核心
2017年第2期386-393,共8页
Journal of Nuclear Agricultural Sciences
基金
国家自然科学基金(31301269)
山西省农业科技攻关项目(20150311016-2)
山西农业大学青年拔尖创新人才支持计划(TYIT201406)
关键词
谷子
拔节期
遮阴
光合特性
产量
foxtail millet, jointing-stage, shading, photosynthetic characteristics, yield
