新疆早熟陆地棉品种更替产量提高过程中冠层结构特征的演变

选用新疆近30年不同年代(1990s、2000s、2010s)早熟陆地棉(Gossypium hirsutum L.)大面积主栽品种,在膜下滴灌栽培条件下,测定其冠层开度、叶倾角、冠层光分布等指标,明确品种更替及产量提高过程中棉花冠层结构的变化特征,为棉花新品种选育及栽培管理提供依据。结果表明,在棉花品种更替及产量提高过程中,不同年代品种生育期相差不大,2010s品种生育期相对较长;盛铃期至吐絮期,2010s的主栽品种冠层开度相对较适宜,光吸收率比1990s和2000s的品种平均高1.06%和5.95%,且生育后期冠层开度、冠层光吸收率均能维持较高水平。2010s品种干物质积累量比1990s和2000s的品种平均高11.51%和15.59%,各器官干物质积累量也呈现增加的趋势。随品种更替叶倾角变化趋势不明显,但不同品种之间差异较大,叶倾角与叶片面积呈负相关。因此,随着棉花品种更替,目前推广品种生育中后期具有适宜的叶面积指数和冠层开度,光吸收率维持在90%左右,总干物质积累量较大是其冠层结构和光合物质生产的重要特征。

Development of Cotton Canopy Structure Characteristics of Cotton Varieties Grown in Different Decades in Northern Xinjiang

Widespread cultivated early maturing upland cotton varieties bred in Xinjiang in different decades (1990s, 2000s and 2010s) were used as experimental materials under mulching drip irrigation conditions. Canopy openness, mean foliage titled angle and canopy light distribution at different growing stages were measured to analyze cotton canopy structural characteristics, which provides a theoretical basis for breeding new cotton varieties and optimizing cultivation management. In the cotton varieties replacement process with yield increase, there was no significant difference in growth stage among different decades, and the growth stage of varieties grown in 2010s was relatively long. In the growth period from full boll stage to boll opening stage, the canopy openness was more reasonable and the light absorption rate was higher for the varieties in 2010s than in 1990s and 2000s; in the late growth period, the canopy openness and canopy light absorption rate for the varieties in 2010s were averagely 1.06% to 5.94% higher than those in 1990s and 2000s. Furthermore, dry matter accumulation of varieties in 2010s was averagely 11.51% to 15.59% higher than that in 1990s and 2000s, with an increasing trend in various organs. There was a consistent changing trend in leaf inclination angle for different varieties, but with a great difference among varieties and closely relating to leaf size. Therefore, with cotton varieties replacing, the appropriate leaf area index and canopy openness at the middle and later stages of cotton growth have been up to about 90% of light absorption now and got more dry matter accumulation, resulting in increased yield.