不同筋型小麦干物质和氮素积累对追施氮量的响应

Response of dry matter and nitrogen accumulation of wheats with different gluten contents to topdressing rate of nitrogen fertilizer

【目的】研究不同筋型小麦干物质和氮素积累对追施氮量的响应,揭示其干物质积累特征,为资源高效利用提供科学参考。【方法】田间试验于2016—2017年在中国农业科学院作物科学研究所北京试验基地进行,供试品种为强筋小麦‘藁优2018’和‘师栾02-1’,中筋小麦‘中麦8号’和‘中麦175’,弱筋小麦‘扬麦22’和‘扬麦15’。在基施纯氮105 kg/hm^(2)的基础上,设N 75、105和135 kg/hm^(2)3个追氮量处理,于拔节期追施。调查分析了小麦花前、花后干物质和氮素的积累与分配,产量及其构成因素。【结果】随着追氮量增加,开花期各筋型小麦干物质积累量均呈增加趋势,但各器官干物质分配比例的变化在不同筋型小麦间不完全相同,其中强筋小麦叶片占比升高,穗占比降低;中筋和弱筋小麦茎秆占比升高,叶片占比降低,穗则先升后降。提高追氮量对成熟期小麦干物质积累的影响主要表现为显著提高了颖壳+穗轴的比例,其他器官占比变化较小,但各器官干物质积累量总体呈增加趋势。随追氮量增加,成熟期各类型小麦营养器官和籽粒氮素积累量、营养器官氮素向籽粒中的转移量呈增加趋势,中筋小麦营养器官花前氮素转运率及贡献率显著降低,强筋和弱筋小麦营养器官花前氮素贡献率逐渐提高;中筋小麦花后氮素转运量显著提高,弱筋小麦花后氮素贡献率则显著降低。增加追氮量可显著提高弱筋小麦穗数、强筋小麦穗粒数、强筋和中筋小麦千粒重;不同筋型小麦产量虽有提高,但差异不显著。【结论】在本试验条件下,强筋小麦干物质积累与分配、氮素积累与转运以追施N 105 kg/hm^(2)为宜,可以保证较高的穗粒数和千粒重,稳定产量。中筋小麦在追施N 135 kg/hm^(2)时,可以显著提高干物质积累、氮素吸收转运及千粒重,保证较高产量。弱筋小麦在追施N 135 kg/hm^(2)时,可以促进植株干物质积累、花前氮素积累与转运,提高对籽粒氮素的贡献率,通过提高成穗数实现产量提升。

【Objectives】The response of dry matter and nitrogen accumulation of wheats having various gluten contents to nitrogen topdressing was studied.【Methods】The experiment was carried out in Beijing Experimental Base,Institute of Crop Sciences at the Chinese Academy of Agricultural Sciences between 2016 and 2017.The tested cultivars were high gluten wheats Gaoyou 2018 and Shiluan 02-1,medium gluten cultivars Zhongmai 8 and Zhongmai 175,and low gluten cultivars Yangmai 22 and Yangmai 15.The three topdressing N rates were 75 kg/hm^(2),105 kg/hm^(2) and 135 kg/hm^(2) at jointing stage,on the basis of basal application of N 105 kg/hm^(2) and P 135 kg/hm^(2).The dry matter and N accumulation before and after anthesis,and the translocation and contribution rate of stored N were investigated.The yield and yield components were also determined.【Results】With the increase in topdressing N rate,the dry matter accumulation of different gluten wheats at flowering stage was increased,but its proportion varied in the vegetative parts.The leaf dry matter in high gluten wheat increased and that in ear decreased;the stem dry matter in medium and low gluten wheats increased,while those in leaves decreased.At maturing stage,increased topdressing N rate significantly increased the dry matter proportion in glume and rachis.The accumulation of N in vegetative organs and grains,whereas the transfer of N from vegetative organs to grains of all types of wheat were increased at maturity.The pre-anthesis N transport rate and contribution rate of vegetative organs of medium gluten wheat were decreased significantly,while the contribution rate of pre-anthesis nitrogen in vegetative organs of high and low gluten wheats were increased gradually.The amount of nitrogen transport after anthesis in medium gluten wheat was increased significantly,while the contribution rate of nitrogen after anthesis of low gluten wheat was decreased significantly.The spike number per spike of low gluten wheat,grain number of high gluten wheat and 1000-grain weight of high and medium gluten wheats were significantly increased by increasing rate of N topdressing.Although the yield of wheat with different gluten types were increased,the difference was not significant.【Conclusions】Under the experimental conditions,N 105 kg/hm^(2) topdressing improved dry matter accumulation and distribution,nitrogen accumulation and transportation of high gluten wheat,which attributed to higher grain number per spike and 1000-grain weight,and stabilize yield.N 135 kg/hm^(2) topdressing significantly improved dry matter and N accumulation and transportation,and yield in moderate gluten wheat.The application of N 135 kg/hm^(2) in low gluten wheat promoted dry matter accumulation,nitrogen accumulation and translocation before flowering,increased the contribution rate to grain nitrogen,and increased yield by increasing the number of spikes.