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在株型育种取得重大突破从而亩产可达千斤以后,进一步提高产量的关键之一将是增加植物单位叶面积的净光合速率.这个特性在过去长期育种过程中不是被淘汰就是被忽视了(Evans,1975).现代的高产育种需要在改进株型的基础上,加强这个生理功能.七十年代初,当C_4—CO_2代谢途径和光呼吸被发现之后,就更加促进了这方面工作的发展.C_4—CO_2代谢途径与C_3—CO_2代谢途径在CO_2交换上主要不同之点,一般表现在净光合速率(P_n)、光呼吸(R_p)、CO_2补偿点(r)上.C_4植物的R_p、r值较低,而P_n较高,C_3植物则与C_4植物相反,R_p、r值较
One of the keys to further increasing yields after a major breakthrough in plant-type breeding and thus a major kilogram of yield will be to increase the net photosynthetic rate per unit leaf area of a plant, a feature that was either neglected or not eliminated in the long-term breeding process Evans, 1975) .In modern high-yielding breeding, it is necessary to strengthen this physiological function on the basis of improving plant type.In the early seventies, C_4-CO_2 metabolic pathway and photorespiration were further promoted in this area. The main differences between the C_4-CO_2 metabolic pathway and the C_3-CO_2 metabolic pathway on CO_2 exchange are generally the net photosynthetic rate (P_n), photorespiration (R_p) and CO_2 compensation point (r) .The R_p, r Value is lower, P_n is higher, C_3 plant is opposite to C_4 plant, R_p, r value is more