Study On Population Matter Production And Development Structure Of Leaf Area And Their Relationships With Yield Formation In Rice

The experiments were carried out in experimental field of Crop Cultivation and Physiology Key Laboratory, from 2000 to 2001. The relationship between matter production,development structure of leaf aera and yield formation was studied with mid-season rice Indica ,cv.shangyou 63 and Japonica, cv.xiangjing 97-3017 as materical. The main results as follows:1. Dry weight of heading stage showed a parabolic curve relationship with yield. And grain yield correlated well with dry matter accumulation after heading and total dry weight of muturing stage. The accumulation of dry matter from N-n to heading stage correlated with photosynthetic potential. And the accumulation of dry matter after heading correlated well with photosynthetic potential and net assimilation. On the base of higher photosynthetic potential.increasing net assimilation was the determinant of enhancing accumulation of dry matter after heading stage.2. Yield showed parabolic curve relationships with LAI of N-n.elongating and heading stage. Growth rate of LAI from N-n to elongating showed a parabolic curve relationship with yield. Growth rate of LAI from elongating to heading correlated with yield. The development of LAI in high-yielding populalion was appropriate LAI at N-n and elongating stage ,higher growth rate of LAI after elongating,appropriate maximal LAI at heading stage and slow decreasing of LAI. In this experiment,the appropriate indices of LAI at N-n .elongating and heading stage were 1.8~2.2,3.9-4.2 and 7.5~7.7. The appropriate indices of LAI-growth-rate from reviving lo N-n, N-n to elongaling, elongating to heading, heading to maturing were 0.09-0.10, 0.09-0.15, 0.15-0.17, -0.10-0.15LAI/d.3.The leaf-area at every breeding stage was constituted of leaf-area of different stems and tillers. Grain yield showed parabolic curve relationships with LAI of N-n andelongating stage. Yield also showed parabolic curve relationships with LAI of tillers of 4 leaf-age and older than 4 leaf-age at N-n and elongating stage. Leaf area index and leaf area constitution at N-n and elongating stage were appropriate in order to have high yield. In this experiment ,LAI of tillers of 4 lea-age and older than 4 leaf-age were about 1.6 and 3.5,84% and 90% of total LALin xiangjing 97-3017;1.8 and 3.8, 81% and 91% of total LAI at N-n and elongating stage in shanyou 63.4.Grain yield showed a parabolic curve relationship with LAI of heading stage. And yield correlated well with the effective leaf area ratio and high effective leaf area ratio. The light transmission ratio was high.chlorophyll content and photosynthetic rate of upper 3 leaves were high, and population photosynthetic ablity was strong. In this experiment, the effective leaf area ratio and high effective leaf area were about 95% and 76% in xiangjing 97-3017;95% and 79% in shanyou 63.5.Appropriate number and constitution of stems and tillers were the base of forming appropriate LAI. Number and constitution of stems and tillers at N-n and elongating stage had close relationship with LAI of N-n .elongating and heading stage. Analyzing above mentioned characteristics, it had multiple regression equations,(1) y=0.2211+0.0801X3+0.129X4(R2=0.921),y was LAI of N-n stage. X3was number of 3 leaf-age tillers, X4 was number of 4 leaf-age and older than 4 leaf-age tillers at N-n stage. (2)y=1.595+0.209X1+0.087X4(R2=0.89), y was LAI of heading stage. X1 was number of total stems and tillers. X4 was number of 4 leaf-age and older than 4 leaf-age tillers at N-n stage.(3)y=12.119-0.035X2-0.062X3(R2=0.88) ,y was LAI of heading stage. XT was the ratio of number of 3 leaf-age tillers to number of total stems and tillers , X3 was the ratio of number of 4 leaf-age tillers to number of total stems and tillers at elongating stage. Relative error were below 6%,verifying above mentioned equations. So equation (1) might estimate LAI of N-n stage, equation (2) and (3) might dope the LAI of heading stage.