黄淮地区稻茬小麦超高产群体特征研究

Population characteristics of super-high-yielding wheat under rice stubble in Huanghuai area

为探讨黄淮地区稻茬小麦超高产（〉9000 kg·hm^-2）群体的生长发育特性,以该区域推广面积较大的半冬性小麦品种‘连麦6号’、‘济麦22’和‘烟农19’为材料,在试验总结出包括基本苗调控和氮肥运筹等一套适宜黄淮地区稻茬麦超高产栽培技术的基础上,建立稻茬小麦高产和超高产群体,对其系列生育、生理特性以及产量要素进行调查分析。结果表明,与高产小麦群体（产量为7380-7889 kg·hm^-2）相比,超高产（〉9000 kg·hm^-2）小麦群体单位面积穗数差异不显著,但穗粒数和千粒重显著增加；超高产小麦抽穗前茎蘖数较高产群体少,但分蘖成穗率较高；超高产群体小麦的叶面积指数,生育前期较高产群体低,抽穗后则显著高于高产群体,两者干物质积累生育前期无明显差异；超高产小麦抽穗期、乳熟期与蜡熟期的根冠比、根系伤流量均显著高于高产群体；超高产小麦粒叶比、茎鞘物质运转率和收获指数均高于高产群体。因此,本文提出了黄淮地区稻茬小麦超高产（〉9000 kg·hm^-2）群体的产量结构与群体指标：单位面积穗数（700±20）×104·hm？2,每穗实粒数〉32,千粒重〉42 g,茎蘖成穗率〉45%；抽穗期叶面积指数6.5-7.0；成熟期总干重〉20700 kg·hm^-2,粒叶比〉14 mg·cm^-2；抽穗期根冠比〉0.28,根系伤流量〉7.1 g·m？2·h^-1；收获指数〉0.45。

Studies on population characteristics of super-high-yielding wheat have recently attracted significant researches. These studies have revealed large differences in wheat population structure in different super-high-yielding wheat areas. The area of wheat under rice stubble in the Huanghuai region has reached 1.3 million hm2, accounting for about 10% of cultivated wheat area in the Huanghuai region. Significant differences have been noted in the growth characteristics and ecological environments between dryland wheat and wheat under rice stubble. Current studies on population characteristics of wheat under rice stubble have focused mainly on production levels of 8 000 kg·hm^-2. Super-high-yielding wheat （yield is higher than 9 000 kg·hm^-2） was still in the infancy development stage, and studies on population characteristics of super-high-yielding wheat under rice stubble in Huanghuai area were less to be reported. To understand the population characteristics of super-high-yielding wheat-after-rice system in Huanghuai region, growth and yield formations of three semi-winter wheat varieties （‘Lianma 6’, ‘Jimai 22’ and ‘Yannong 19’） were investigated under high-yield （CK） and super-high-yield （SHY） cultivation measures. The results showed that wheat varieties had more grains per spike and higher 1000-grain weight under SHY than under high-yield wheat CK. There was no significant difference in spike number per＆amp;nbsp;unit area between SHY and CK. Compared with those under CK, wheat exhibited fewer tillers at the early growth stage （from tillering to jointing） but with higher rate of productive tillers to total tillers under SHY. While leaf area index and photosynthetic potential of SHY were lower than those of CK at the early growth stage, these attributes were significantly higher after heading. There was no significant difference in accumulated dry matter weight between SHY and CK at the early growth stage. Root-to-shoot ratio and root exudate amount under SHY were higher than those under CK at heading, milking and waxing stages. Also grain-to-leaf ratio, percent matter translocation from stem and sheath, and harvest index under SHY were higher than those under CK. Analysis of various attributes of rice yield and population showed that for SHY wheat in Huanghuai region, spikes per unit area, grains per spike, 1000-grain weight, productive tiller rate, total dry matter weight at maturity stage, grain weight/leaf area ratio, root/shoot ratio at heading stage, root exudate amount, harvest index were greater than 700×104·hm^-2, 32, 42 g, 45%, 20 t·hm^-2, 14 g·cm^-2 （i.e., mg grain weight per cm2 leaf area）, 0.28, 7.1 g·m^-1, 0.45, respectively; while leaf area index at heading stage was 6.5-7.0.