稻茬小麦公顷产量9000kg群体糖氮代谢特征

Sugar-Nitrogen Characteristics of Wheat at Yield Level of 9 000kg·hm^(-2) Following Rice

【目的】探讨稻茬小麦籽粒产量9 000 kg·hm-2群体糖氮代谢特征及关键生育期糖氮营养诊断指标。【方法】2010—2012年,在稻麦两熟条件下,以中筋小麦扬麦20为材料,采用三因素裂区设计,以施氮量(纯N)为主区,设210 kg·hm-2、262.5 kg·hm-2两个水平;以施氮比例为副区,设基肥﹕壮蘖肥﹕拔节肥﹕穗肥分别为3﹕1﹕3﹕3、5﹕1﹕2﹕2两个水平;以穗肥追氮时期为裂区,设剑叶露尖、孕穗期、抽穗期和开花期4个水平。通过试验构建稻茬小麦不同产量群体,分析不同产量群体植株可溶性糖、氮含量及糖氮比动态特征及其与产量的关系,提出籽粒产量9 000 kg·hm-2左右稻茬小麦关键生育期糖氮代谢诊断指标。【结果】随小麦生育进程推移,不同产量群体植株可溶性糖含量及糖氮比在越冬始期和孕穗至开花期出现峰值,返青期出现低谷,花后下降直至成熟;植株氮含量逐渐下降,其中越冬始期至拔节期迅速降低,拔节至孕穗期降幅减慢,孕穗期至成熟期缓慢下降。籽粒产量9 000 kg·hm-2以上群体孕穗期植株可溶性糖、氮含量及开花期植株氮含量显著高于籽粒产量9 000 kg·hm-2以下群体;成熟期植株可溶性糖含量低于籽粒产量9 000 kg·hm-2以下群体,2010—2011年度差异达显著水平,2010—2011年度差异未达显著水平;成熟期植株糖氮比显著低于籽粒产量9 000 kg·hm-2以下群体;其他生育期植株可溶性糖、氮含量及糖氮比群体间差异均未达显著水平。孕穗期植株可溶性糖、氮含量及开花期植株氮含量与产量呈线性正相关,乳熟期植株可溶性糖及氮含量与产量呈抛物线关系,成熟期植株可溶性糖含量与产量呈线性负相关。籽粒产量9 000 kg·hm-2左右群体孕穗期、开花期、乳熟期及成熟期植株可溶性糖含量分别为14.56%—16.78%、14.52%—16.82%、10.59%—11.23%、1.62%—1.76%,氮含量分别为1.55%—1.64%、1.47%—1.57%、1.28%—1.30%、1.15%—1.20%,糖氮比分别为9.37—10.25、9.80—10.69、8.29—8.77、1.41—1.48。【结论】稻茬小麦实现籽粒产量9 000 kg·hm-2需要在越冬始期至拔节期具有较高的糖、氮营养和协调的糖氮比,关键在于孕穗期至开花期具有高可溶性糖及氮含量,开花后具有高碳素积累量及向籽粒的转化率。

[Objective]The sugar-nitrogen characteristics of wheat at yield level of 9 000 kg＆#183;hm-2 following rice were studied. In addition, the sugar-nitrogen nutrition diagnosis indexes for wheat at yield level of 9 000 kg＆#183;hm-2 were suggested. [Method]Wheat populations at two different yield levels in rice-wheat rotation, including ＆lt;9 000 kg＆#183;hm-2 population （hereinafter as HY） and≥9 000 kg＆#183;hm-2 population （hereinafter as SHY）, were established by agronomic management of the medium-gluten wheat, Yangmai 20 （Triticum aestivum L.）. From 2010 to 2012, field experiments were conducted as split-plot design at 16 combinations of two applications of nitrogen amount （210 kg＆#183;hm-2 and 262.5 kg＆#183;hm-2）, two nitrogen applied ratios of basis﹕tillering﹕elongation﹕booting （3﹕1﹕3﹕3 and 5﹕1﹕2﹕2）, and four nitrogen topdressing stages （flag leaf stage, booting stage, heading stage and anthesis）. The dynamics of soluble sugar content, nitrogen content and soluble sugar to nitrogen ratio （hereinafter as C, N and C/N） in plant population of different yield levels were analyzed. And at different growth stages, the relationship between plant C, N and C/N and grain yield were analyzed, respectively. In addition, the sugar-nitrogen nutrition diagnosis indexes for wheat at yield level of 9 000 kg＆#183;hm-2 were suggested. [Result] As the developmental process goes on, the plants C and C/N had two peak values at the beginning of over-wintering stage and at stage from booting to anthesis, and a low value at green-turning stage. Then, the plants C and C/N showed a gradual decrease after anthesis. The plants N, however, showed a gradual decrease during the growth period -rapid decrease during the period between the beginning of over wintering stage and elongation stage, slow decrease during the period between elongation stage and booting stage, and slow decrease during the period between booting stage and maturity stage. In SHY plants, C and N at booting and N at anthesis were significantly higher than those of HY. But C at maturity was significantly lower than those of HY in 2010-2011, and not-significantly lower than those of HY in 2011-2012. In addition, C/N at maturity was significantly lower than those of HY. Plants C and N at booting stage and N at anthesis were in a positive linear correlation with grain yield. Plants C and N at milk-ripe stage were in a parabolic cure relationship with grain yield. Plants C at maturity were in a negative linear correlation with grain yield. The sugar-nitrogen nutrition diagnosis indexes for the population of about 9 000 kg＆#183;hm-2 were suggested. At the stages of booting, anthesis, milk-ripe and maturity, C were 14.56%-16.78%, 14.52%-16.82%, 10.59%-11.23%and 1.62%-1.76%, respectively, N were 1.55%-1.64%, 1.47%-1.57%, 1.28%-1.30% and 1.15%-1.20%, respectively, and C/N were 9.37-10.25, 9.80-10.69, 8.29-8.77 and 1.41-1.48, respectively. [Conclusion] Compared with HY, from the beginning of over wintering stage to elongation, C and N in SHY plants were generally high, and C/N was relatively suitable. From booting stage to anthesis, C and N in SHY plants were significantly higher. After anthesis, SHY plants could accumulate more sugar and had a higher conversion rate of sugar to grain yield as compared with HY.