宁夏不同生态区小麦碳同位素分辨率与产量、收获系数和物候期的相关研究

Study on the relationships between carbon isotope discrimination and yield,harvest index and phenology of wheat planted in different ecological areas of Ningxia

在宁夏灌区设3个试验点,即银川(有限灌溉条件)、惠农(有限灌溉+盐碱条件)、固原(雨养条件)(银川2个点,惠农1个点),于2005年春小麦生长季,研究了20份春小麦材料旗叶和籽粒的碳同位素分辨率(Δ)、物候期、产量、生物量、收获指数等指标的表现及相互关系.结果表明:由于土壤含水量、气候条件不同,3个试验点间各项测定的指标均有显著差异,表现为有限灌溉条件下的产量、Δ值、生物量及收获指数高于雨养条件.有限灌溉条件下的银川和惠农试点的叶片Δ及籽粒Δ均与产量呈正相关,雨养条件下的固原试点的叶片Δ与产量不相关,籽粒Δ与产量呈弱的负相关.3个试验点的Δ与收获指数均呈正相关,与从出苗到抽穗的天数以及到成熟的天数呈负相关.Δ有希望作为水分限制条件下预测小麦产量的间接选择指标.

Twenty experimental sites spring wheat genotypes collected in north- western China were grown in three in Ningxia： Yinchuan （limited irrigated condition）, Huinong （limited irrigated ＋ salinity condition）, Guyuan （rain--feed condition）. Carbon isotope discrimination （△） of flag leaf at heading stage （△La） and grain at maturity （△Gm）, harvest index （HI）, and yield were measured and phenology was recorded. The result showed that the value of traits measured showed significant difference across the three sites. The grain yield, △ value, biomass and harvest index under limited irrigation were higher than those under rain-fed condition. Both △La and △Gm correlated positively with yield under limited irrigated conditions （Yinchuan and Huinong）, while no correlation between △La and yield was noted and negative correlation trend between △Gm and yield were found under rain-fed condition （Guyuan）. △ correlated positively with HI in all the three sites. The number of days from emergence to heading stage （DH） and maturity （DM） exhibited negative correlations with △. Our result indicated that the △could be used as an indirect criterion to predict the yield of wheat genotypes under water stress environment.