群体冠层结构对棉花光合特性及产量性状的影响效应研究

Effects of canopy structure on photosynthesis and yield in cotton

以‘硕杂棉2号’为试验材料,通过化控技术和分期打顶结合的方式塑造出矮冠层(L)、波浪冠层(W,高矮相间)和高冠层(H)3个不同冠层结构的处理,研究各处理的透光率、群体光合速率、干物质积累、烂铃率和产量等。结果表明:在生育中后期,L和H冠层结构的中下层透光率显著低于W冠层;W冠层干物质积累总量比L高13.52%,其中营养器官比L冠层高20.87%,比H冠层低7.95%,生殖器官比L冠层高15.34%,比H冠层高10.43%;烂铃率与脱落率W冠层处于L冠层和H冠层中间水平;单铃重W冠层比L和H冠层高7.91%和8.10%;W冠层的产量略高于L,比H冠层提高12.08%。说明波浪冠层(W)棉花冠层结构的中下部由于获得更多的光照,降低群体烂铃率和脱落率,提高全株光合产物的积累,最终促进了棉花的生殖生长,获得较高产量。

Using hybrid cotton‘Shuoza 2＇as the test variety,three different canopy structures of dwarf type（L）,wave type（W）and high type（H）were created through chemical control and top-cutting,and their light transmittance,photosynthetic rate,dry matter accumulation,ball rot rate and yield components were studied.The results indicated that,in the late growth period,the light transmittance at the middle and bottom canopy positions of the L and H canopy structures was significantly lower than that of W canopy.Compared with W canopy,the total dry matter accumulation of L canopy was decreased by 13.52%.Among them,the vegetative organs of L canopy decreased by 20.87%,H canopy increased by 7.95%,the reproductive organs of L canopy decreased by 15.34%,and H canopy decreased by 10.43%.The bollrot rate and the dropout rate of W canopy were at an intermediate level between L and H canopy structures.The boll weight of W canopy increased by 7.91% and 8.10% than that of L and H canopy ones.The theoretical yield of W canopy structure increased by 12.08% than that of H canopy structure.The test results indicated that the higher light transmittance at the middle and bottom canopy positions of W canopy structure guaranteed the lower rate of boll rot and boll dropping rate,and improved the accumulation of the whole plant photosynthetic products,and ultimately promoted cotton reproductive growth for higher yield.