低醇溶蛋白转基因大麦氮素转移特征

Nitrogen Transfer Characteristics of Low Prolamin Transgenic Barley

为探究氮肥施用量对低醇溶蛋白转基因大麦花后各营养器官氮素积累、分布及转运的影响,明确大麦花后至籽粒形成过程中氮素的变化规律,采用土培盆栽试验,利用前期筛选出已稳定遗传的低醇溶蛋白转基因大麦为试验材料,以其受体为对照,分析二者分别在不施氮、低氮(160 mg N·kg^(-1)土)、正常氮(230 mg N·kg^(-1)土)和高氮(300 mg N·kg^(-1)土)4个氮素处理下的籽粒产量、生物量及花后营养器官氮素积累及转运特性。结果表明,相同施氮量下,转基因大麦的籽粒产量和地上部生物量高于对照,而株高和千粒重较对照显著降低,有效穗数和每穗粒数较对照显著增加;即与受体相比,转基因大麦通过增加分蘖数和有效穗数补偿产量配给,实现增产。转基因大麦籽粒的蛋白含量显著低于对照,较对照降低0.58%~2.40%;且随着施氮量增加,籽粒蛋白含量逐渐增加。转基因大麦各营养器官的氮素含量表现为穗>叶>茎秆,且在穗中氮素含量在扬花期最高。不同时期植株地上部的氮素积累量表现为扬花期>灌浆期>成熟期,说明扬花期是影响大麦氮素再利用的关键时期,且转基因大麦的籽粒产量与扬花期穗氮素含量呈显著正相关。以上结果为大麦氮素转运的生理机制及生产施肥实践奠定了理论基础。

In order to explore the effects of nitrogen fertilizer application on nitrogen accumulation,distribution and transport in various vegetative organs of low prolamin transgenic barley after anthesis,to clarify the pattern of nitrogen changes from after barley anthesis to grain formation,the soil culture pot experiment was carried,and the genetically stable low-gliadin transgenic barley was as the test material with the receptor as the control(CK).The four nitrogen applications were set including no nitrogen,low nitrogen(160 mg N·kg^(-1) soil),normal nitrogen(230 mg N·kg^(-1) soil)and high nitrogen(300 mg N·kg^(-1) soil).The grain yield,biomass and nitrogen accumulation and transport characteristics in vegetative organs after anthesis were determined.The results showed that,under the same nitrogen treatment,the grain yield and above-ground biomass of transgenic barley were higher than CK,plant height and 1000-grain weight were significantly lower than CK,and the number of effective panicles and the number of grains per panicle significantly increased.The grain yield increased by increasing the number of tillers and effective panicles.And the protein content of genetically modified barley grains was significantly lower than CK with decrease of 0.58%~2.40%.With the increase of nitrogen application rate,the grain protein contents increased,the accumulation content of nitrogen in the vegetative organs of transgenic barley showed ear>leaf>stalk,and the highest nitrogen content in the panicle was at the blooming stage.The accumulation amount of nitrogen in above ground plant showed blooming period>filling period>maturity period,which indicated that the blooming period was the critical period affected barley nitrogen reuse.The significant correlation between grain yield and spike nitrogen content at the blooming stage was detected.Above results laid a foundation for the physiological mechanism of barley nitrogen transport and production and fertilization practices.