增施有机肥对冬小麦同化物积累与分配的影响

Effects of organic fertilizer application on accumulation and distribution of assimilates in winter wheat

基于13CO2脉冲标记法,设置单施化肥(CF)和有机肥+化肥(OF)两个处理,通过分析不同施肥模式对麦田土壤和小麦植株中的有机碳含量、光合特性和同化物转化的影响,探讨增施有机肥对冬小麦同化物积累与分配的影响.结果表明:OF处理有利于提高麦田土壤有机碳含量和小麦光合特性,从而提高了小麦植株有机碳含量和干物质积累总量.同一时期标记至成熟与标记后第7天相比,两个施肥处理下叶和茎鞘中的13C含量与13C分配率均减少;穗部13C含量在拔节期和灌浆期均增加,开花期均减少,13C分配率各时期均增加.两个施肥处理相比,OF处理有利于灌浆期光合碳向穗部转运与积累,提高小麦穗部的13C分配率.相关分析结果表明,干物质积累量与净输入13C含量、净输入13C分配率呈极显著正相关关系,与植株中有机碳含量呈负相关关系;净输入13C含量与净输入13C分配率呈极显著正相关关系,与光系统II的最大光能转化效率(Fv/Fm)和净光合速率(Pn)呈负相关关系.综上,增施有机肥能增加麦田土壤有机碳含量,提高小麦的光合能力和光合产物向穗部的转运,最终有利于小麦穗部的同化物积累.

To understand the effects of organic fertilizer addition on accumulation and distribution of winter wheat assimilates,we compared organic carbon content in soil and wheat plants,photosynthetic characteristics and assimilation transformation under two different fertilizer treatments,CF(chemical fertilizer only)and OF(organic fertilizer with chemical fertilizer),using 13CO2 pulse labeling method.The results showed that OF increased soil organic carbon content and wheat photosynthetic parameters,resulting in higher organic carbon content and total dry biomass accumulation in wheat plants compared with CF treatment.Compared marking to maturity with that on the 7 th day after the same marking,the content and distribution rate of 13C in leaves and stems of two treatments decreased;the 13C content in spikes increased at jointing stage and filling stage,decreased at anthesis stage,and the 13C distribution rate increased at all stages.OF treatment was more beneficial for the transportation of photosynthetic product from leaves to spikes at filling stage,with higher 13C distribution rate in spikes compared with CF treatment.The results of correlation analysis showed that dry matter accumulation was significantly positively correlated with the net input of 13C content and its distribution rate,but negatively correlated with organic carbon content in plants.The net input of 13C content was significantly positively correlated with its distribution rate,and negatively correlated with Fv/Fm and Pn.In conclusion,organic fertilizer application could increase the content of organic carbon in soil,improve wheat plants photosynthetic capacity and transportation of photosynthetic product to spikes,and ultimately increase dry matter accumulation in wheat spikes.