【作者】 李涛；

【导师】 龚月桦；

【作者基本信息】 西北农林科技大学 ， 植物学， 2009， 硕士

【摘要】 为了阐明持绿小麦碳氮同化物的转运与分配规律及干旱对其影响,本文以持绿型小麦豫麦66（YM66）,早衰型小麦温麦6号（WM6）,对照品种小偃22（XY22）作为试验材料进行盆栽试验。以称重控水法进行干旱处理,利用¹⁴C放射性同位素示踪技术和¹⁵N非放射性同位素技术进行花前和花后标记,研究不同持绿型的小麦,在灌浆期碳氮同化物的转运分配规律以及干旱对其影响。以阐明持绿型小麦同化物的生产、转运特性,为挖掘持绿型小麦的潜能提供理论依据。所得主要结果如下:1.花前¹⁴C标记表明,小麦花前标记的¹⁴C-贮备物在开花时80%-90%已储存于茎鞘和颖壳中,仅有约10%-20%残留在叶片中;开花后这些贮备物都向籽粒转运,成熟时籽粒中¹⁴C分配率约为20-40%,茎杆与颖壳中含有约60%-80%,极少量残留在叶片中。持绿型小麦YM66的¹⁴C-贮备物从叶片和茎杆中输出得快,成熟时籽粒含有40%的¹⁴C-贮备物,高于对照品种XY22和早衰品种WM6。对于YM66和XY2,干旱处理促进了¹⁴C-贮备物向籽粒中的转运。2.小麦花后¹⁴C标记表明,在标记后12h,¹⁴C-同化物有40%-60%储存在茎鞘和颖壳中,20%-50%储存在籽粒中,仅有15%-25%残留在叶片中,不同持绿性小麦之间¹⁴C分配率差异较大;此后,叶片和茎鞘中的¹⁴C向籽粒转运,成熟时,籽粒中¹⁴C同化物的分配率为40%-80%,YM66和XY22籽粒中的¹⁴C-同化物高达70%-80%,而WM6却只有40%-50%,对于YM66和XY22。干旱处理下,籽粒中¹⁴C-同化物的分配率要高于正常水分处理的,而WM6则相反。3.花前¹⁵N标记表明,小麦花前标记的¹⁵N-贮备物在开花时45%-60%储存于茎鞘和颖壳中,约有40%-55%仍留在叶片中;开花后茎鞘,颖壳和叶片中的¹⁵N都向籽粒转运,成熟时籽粒中¹⁵N分配率约为45-65%,茎鞘与颖壳中含有约15%-25%,有20%-40%残留在叶片中。成熟时YM66籽粒中¹⁵N分配率最低,XY22最高。干旱胁迫使¹⁵N-贮备物在籽粒中的分配率升高,说明干旱促进了花前N的转运。4.花后¹⁵N标记表明,在标记后12h, ¹⁵N-同化物有50%-70%储存在茎鞘和颖壳中,有30%-50%留在叶片中;在12h-24h,叶片中¹⁵N分配率升高,此后,叶片和茎鞘中¹⁵N分配率持续下降;成熟时,籽粒中¹⁵N同化物的分配率为50%-65%,茎鞘中为15%-25%,叶片残留30%-35%。干旱胁迫使YM66和XY22 ¹⁵N-同化物在籽粒中的分配率有所增加。5.开花后各个小麦品种叶片和茎鞘全氮含量呈下降趋势,籽粒全氮含量则先升后降。茎鞘中,持绿型品种YM66的全氮含量高于对照,WM6的最低,在叶片中则WM6和YM66的全氮含量较高,XY22的最低。籽粒中XY22的最高,YM66的最低。对于XY22和YM66,干旱降低了叶片和茎鞘中全氮含量,而增加了籽粒中的全氮含量。成熟时持绿小麦YM66总生物量和籽粒产量均高于非持绿品种,其中总生物量比对照品种提高了约10%。更多还原

【Abstract】 Transportation and distribution of carbon and nitrogen assimilates in wheat under drought stress was studied by ¹⁴C-labeling and ¹⁵N-labeling.The materials are YM66 （stay-green）, WM6（senescent） and XY22（control）.The experiment was conducted by labelling leaf with ¹⁴CO₂ before and after anthesis to elucidate the effect of drought on different kinds of stay-green wheat by control water.Also the another study was conducted with ¹⁵N labeling leaf before and after anthesis to show transportation and distribution of nitrogen assimilates under drought stress.Our purpose was to elucidate the traits of production and distribution of carbon and nitrogen assimilates.The results are as follows:1.The experiment of ¹⁴C-labeling before anthesis showed that about 80%-90% of ¹⁴C-reserves had been stored in the stems and rachises, and about 10%-20% remained in the leaves at anthesis;After anthesis, these reserves were remobilized and transported to the kernels. At maturity, ¹⁴C-reserves in the leaves were exported almost entirely, but about 60%-80% ¹⁴C-reserves remained in the stems and rachises, and about 20%-40% was imported into the kernels. The ¹⁴C-reserves in stay-green wheat were transported more quickly from the leaves and stems, and at maturity ,the stay-green wheat YM66 has imported 40% of ¹⁴C-reserves into the kernels, much more than XY22 and WM6.Drought stress promoted translocation and distribution of ¹⁴C-reserves into the kernels of YM66 and XY22.2.The experiment of ¹⁴C-labeling after anthesis showed that about 40%-60% of ¹⁴C-assimilates was stored in the stem and sheath after 24 hours, 20%-50% was transported into the kernels, and about 15%-25% remained in leaves.Then,these assimilates were remobilized and transported to the kernels.At maturity,about 40%-80%¹⁴C was found in the kernels.It is up to70%-80% in YM66 and XY22 ,but 40%-50% in the WM6.For YM66 and XY22,the distribution of kernels under drought was higher than normal,but WM6 is opposite.3.The experiment of ¹⁵N-labeling before anthesis showed that about 45%-60% of ¹⁵N-reserves assimilated before anthesis had been stored in the stems and rachises, and about 40%-55% remained in the leaves at anthesis;After anthesis, these reserves were remobilized and transported to the kernels, at maturity, about 15%-25% ¹⁵N reserves remained in the stems and rachises, and about 45%-65% was imported into the kernels,20%-40% remained in the leaves.The distribution of YM66 in kernels is lower than others,but XY22 is higher. The drought promote the distribution in kernels.4.The experiment of ¹⁵N-labeling after anthesis showed that about 50%-70% of ¹⁵N -assimilates was stored in the stem and sheath,about 30%-50% remained in the leaves.After 24 hours,distribution of leaves increasd first ,then got lower,and distribution of the stem and sheath always decreased.At maturity,about 50%-65%¹⁵N was found in the kernels, 15%-25% in the stem and sheath and30%-35% in the leaves. The drought promote the distribution of YM66 and.XY22 in kernels.5.After anthesis, The nitrogen content of leaves and stems has decreased,and the stay-green wheat YM66 had higher nitrogen level than XY22,and WM6 has lowest nitrogen content. The nitrogen content of kernels first increased and then decreased.In YM66 and XY22,the drought promote the nitrogen content in kernels and reduced the nitrogen content in leaves, stems and rachises. At maturity, Total Biomass and Seed Yield of YM66 is higher than XY22 and WM6.更多还原