施氮及花后土壤相对含水量对黑粒小麦灌浆期 氮素吸收转运及分配的影响

以黑粒小麦‘漯珍一号’为供试材料,通过棚下盆栽试验研究了不同施氮量及花后土壤相对含水量对‘漯珍一号’植株氮素吸收、转运、分配以及籽粒蛋白质及其组分含量的影响。结果表明:相同施氮量下,黑小麦籽粒含氮量、蛋白质积累量随水分胁迫加剧而降低;各蛋白质组分含量的变化随施氮量的不同而存在差异,在低氮N_1,150 kg(N)·hm~(-2)]条件下,随水分胁迫加剧,清蛋白、球蛋白、醇溶蛋白含量升高,高氮N_3,300 kg(N)·hm~(-2)]条件下,清蛋白、球蛋白含量升高,而醇溶蛋白含量降低。相同水分胁迫(土壤相对含水量为55%~65%,W_2;土壤相对含水量为35%~45%,W_3)条件下,籽粒氮素含量、籽粒中蛋白质的积累量随施氮量增加而提高,成熟期籽粒氮素含量占总氮素含量的比例下降;而充足供水(土壤相对含水量为75%~85%,W_1)时,中氮处理N_2,240 kg(N)·hm~(-2)]籽粒蛋白质积累量最高,同时,营养器官贮藏氮素向籽粒的转运量、转运率均达最大值,对籽粒的贡献率也较高。W_1处理时,清蛋白、球蛋白和醇溶蛋白含量随施氮量的增加而提高,麦谷蛋白在N_2处理达最大值;而W_2、W_3处理情况下,N_2处理小麦中各蛋白质组分含量最高。综上所述,本试验条件下,施氮量及花后土壤相对含水量对黑粒小麦氮代谢具有显著影响,施氮量过高或过低以及水分胁迫均不利于黑粒小麦氮代谢过程的有效进行,综合考虑,花后充足供水(W_1)与中等施氮水平(N_2)组合对黑粒小麦氮素吸收、转运和分配具有较好的调控作用。

Effect of nitrogen fertilization and soil relative water content after anthesis on nitrogen absorption and translocation of black wheat

AbstractBlack wheat variety ‘Luozhen 1’, a colored wheat variety, was higher in nutritional value and exploring potential. However, its low yield was the main limiting factor of plantation due to weak photosynthetic capacity and matter translocation ability at key stages of yield forming. In order to provide the theory basis for high yield cultivation of black wheat, a pot experiment was carried out to study the effect of nitrogen rate and soil relative water content after anthesis on nitrogen absorption and translocation of black wheat ‘Luozhen 1’ at the station of the Institute of Crop Science of Chinese Academy of Agricultural Sciences in 2014–2015. Two factors were set in the experiment, nitrogen fertilization rate 150 kg(N)·hm?2(low N level, N1), 240 kg(N)·hm?2(middle N level, N2), 330 kg(N)·hm?2(high N level, N3)] and soil relative water content after anthesis 75%-85% (adequate water supply treatment, W1), 55%-65% (middle water stress, W2) and 35%-45% (serious water stress, W3) of field capacity]. The results showed that grain nitrogen content and protein accumulation amount declined with decreasing soil relative water content under the same nitrogen fertilization rate. Protein components contents varied with different nitrogen fertilization rates and soil relative water content. The contents of albumin, globulin and prolamin increased with declining soil water content in low N level (N1). In high N level (N3) treatment, albumin and globulin contents also increased with declining soil water content, while prolamin content decreased. Under soil water stress conditions (W2, W3), nitrogen content, protein accumulation amount in seeds increased and the percentage of grain nitrogen content at maturity declined with increasing nitrogen fertilization rate. However, under adequate water supply (W1), protein accumulation amount, nitrogen translocation efficiency from nutritive organs to grain and nitrogen translocation amount were highest under middle N level (N2). Albumin, globulin and prolamin contents also increased with increasing nitrogen fertilization rate under W1 condition, while glutenin reached the highest level in N2 treatment. Under water stressed conditions (W2 or W3), all protein components were highest in N2 treatment. It was concluded that there were significant impact of nitrogen rate and soil water content after anthesis on nitrogen metabolism of black wheat ‘Luozhen 1’. Nitrogen application rate of 240 kg×hm?2 and adequate water supply were recommended in the experimental condition due to effective nitrogen metabolism process.