摘要
增加有效分蘖数被认为是提高小麦 (Triticumaestivum)产量的重要方法之一 ,但是小麦种群在生长进程中也会形成大量的无效分蘖 ,存在“生长冗余”。研究了覆膜栽培对两个春小麦种群中无效分蘖比率和收获指数的影响 ,并从植物个体大小不整齐性和生活史策略的种群生态学角度探讨其影响机制。与露地对照相比 ,覆膜栽培能显著提高春小麦产量 (+38.5 %) ;产量的提高源于地上部分生物量 (+4 4.7%)的显著增加。但是 ,覆膜种群的繁殖分配 (穗重 /地上部分生物量 ,- 5 .2 %)和收获指数 (- 4.5 %)显著降低 ;在几个主要生育期里 (拔节期、开花期和成熟期 )覆膜种群中无效分蘖数及无效分蘖生物量比率均显著大于露地对照。说明覆膜种植加剧了春小麦种群的生长冗余。地膜覆盖与其对照的Gini系数动态有显著差异 ;其中在拔节期与开花期覆膜处理高于对照 ;在成熟期覆膜处理低于对照 ;并且 ,种群的繁殖分配和收获指数都与种群的平均Gini系数 (4个生育期的均值 )呈显著的负相关。我们认为覆膜种群中生长冗余的显著增加 (繁殖分配的下降及无效分蘖生物量的增加 ) ,是由于覆膜处理促进分蘖的过度发生和生长、造成群体密度过高、个体大小不整齐性增加从而使种群内个体间竞争加剧的结果。由此表明 ,伴随着产量的显著提高 。
Spring wheat (Triticum aestivum) plants normally produce tillers, many of which do not survive to produce grain-bearing spikes. Increasing the percentage of tillers that survive has hypothesized as an approach for increasing yield of wheat plants. This study was conducted to determine the effects of plastic film mulch on percentage of abortive tillers and harvesting index in two spring wheat populations, and to explore its mechanism in relation to size inequality and life-history strategies theory. Field-grown spring wheat mulched with plastic film showed a remarkable increase in grain yield (+38.5% of non-mulched control averagely), which mainly resulted from the significant increase in above ground biomass (+44.7%). At the same time, however, reproductive allocation (spike weight/above ground biomass, -5.2%) and harvesting index (-4.5%) were significantly lower (p<0.05) in mulched than unmulched populations in both 2 cultivars. Meanwhile, the number and weight of barren shoot and the ratio of barren shoot biomass were significantly greater in mulched populations than unmulched controls both at booting, flowering and ripening stages. From tilling to ripening stages, the trend of G (Gini coefficient) showed obvious differences between mulched populations ('∧' type with the peak of G at booting stages) and non-mulched controls ('∨'type with the lowest G at flowering and rebounded at ripening stage). At booting and flowering, the G was significantly higher in mulched populations than unmulched controls, and it was just contrary at ripening. Reproductive allocation and harvesting index (HI) were both negatively correlated to average G of the populations. From these results, we concluded that appreciable growth redundancy occurred in spring wheat populations mulched with plastic film may result from the exacerbated inter-plant competition and self-thinning (evidenced by increasing in the degree of Gini coefficient at booting and flowering stages). Thus, spring wheat cultivation with plastic film mulching does not always mean efficiency, although there is a remarkable increase in grain yields.
出处
《植物生态学报》
CAS
CSCD
北大核心
2002年第2期177-184,共8页
Chinese Journal of Plant Ecology
基金
国家自然科学基金项目 ( 90 10 2 0 15
30 170 16 1)
国家重点基础研究专项经费 (G19990 1170 5 )
关键词
个体大小不整齐性
生长冗余
春小麦种群
地膜覆盖栽培
收获指数
Size inequality, Growth redundancy, Spring wheat (Triticum aestivum) populations, Plastic film mulching, Harvesting index
