抗虫棉、彩色棉光合特性及其与生态、生理因子相关性研究

Study on Photosynthetic Characteristic of Cotton (Gossypium hirsutum L. ) and Its Relation to Ecologic and Physiologic Factors

在大田种植条件下,采用Li-6400P光合作用测定系统,研究了不同天气状况下,转Bt基因抗虫棉、彩色纤维棉和普通棉3种类型的陆地棉(Gossypium hirsutum L)光合速率日变化特征,并对光合速率与7个生态、生理因子间相关性进行了数学模拟,提出用品种依存度(VDF)、因子影响频度(FAF)分别描述品种适应性、因子的影响大小,用缺乏型、富裕型限制因子描述因子的影响方向。结果表明:光合速率日变化特征依天气、品种不同而异。正常天气时光合作用强度高,光合速率日变化曲线为单峰曲线;高温、干旱等逆境条件下光合作用强度大为降低,光合速率日变化曲线为双峰曲线。普通棉(华抗棉1号)适应性较差,VDF最高,为21％。彩色棉抗逆性较强,VDF最低,为9％左右,但正常条件下光合能力有限;抗虫棉适应性(VDF为16％左右)介于普通棉和彩色棉之间。不同条件下,对光合速率起主导作用的生态、生理因子不同,即各因子的影响频度不同。蒸腾速率始终是缺乏型限制因子,FAF为60％,说明棉花蒸腾系数大,是需水量较大的作物。细胞间隙CO2浓度与光合速率成负相关,FAF为65％。土壤水分含量较高时,光照强度成为缺乏型限制因子。高温、干旱等逆境时,气孔导度、大气CO2浓度是缺乏型限制因子,温度、光照是富裕型限制因子。

Three types of field-grown cotton (Gossypium hirsutum L. ), Bt-transgenic boll-worm resistant variety, colored lint variety and conventional variety were examined for their characteristic of diurnal photosynthesis by using Li-6400 portable photosynthesis system under different weather condition. Simulation was conducted on photosynthetic rate and 7 ecologic and physiologic factors . VDF and FAF were put forward to describe the adaptation to the environment of the varieties and the affluent degree of factors respectively. Deficit or luxury inhibiting factor was used to describe the influent direction. The result showed that: 1) The feature of diurnal variation of photosynthesis varied with weather and varieties . The photosynthesis was strong, and the photosynthetic curve was a single-peak one under normal weather condition, but the photosynthesis was much weak, and the curve was a double-peak one under stress conditions, such as high temperature and draught. Conventional variety (Huakang mian No. 1), with the highest VDF of 21%, had a weak adaptation. While colored lint variety, with the lowest VDF of 9%, had a good resistance to stress, but a weaker photosynthesis under normal condition. Bt-transgenic boll-worm resistant variety, with a VAF of 16%, had a moderate adaptation to stress compared to the rest; 2) The inhibiting factors to photosynthesis varied from natural conditions among those 7 ecologic and physiologic factors, with a different FAF. Transpiration rate, 60% of FAF, was a deficit inhibiting factor all the way, revealing that cotton had a high transpiration coefficient, and was a water urgently demanding crop. Ci correlated negatively to photosynthesis, with the highest FAF of 65%. Also PAR became the deficit inhibiting factor under the condition of affluent soil moisture, but PAR and temperature were luxury inhibiting factors, whereas stoma conductance and CO2 concentration in the air were deficit inhibiting factors under stress conditions such as high temperature, drought, etc.