两种穗型小麦品种分蘖衰亡进程中茎蘖碳氮代谢的差异

Difference of Carbon and Nitrogen Metabolism in Leaves between Main Caulis and Tillers during Tiller Senescence of Two Spike-type Winter Wheat

以大穗型品种兰考矮早八和多穗型品种豫麦49-198为材料,研究2种穗型小麦品种茎蘖叶片糖氮代谢差异及与分蘖成穗间的关系。结果表明,兰考矮早八较豫麦49-198具有冬前分蘖比重低、春季分蘖比重高、无效分蘖春季衰亡持续时间长和分蘖成穗率低的特点。兰考矮早八氮素代谢相对较弱,茎蘖叶片氮含量、氨基酸含量和谷氨酰胺合成酶(GS)活性均明显低于豫麦49-198,不利于大穗型品种春季分蘖幼穗分化顺利进行。兰考矮早八植株碳素代谢相对较强,茎蘖叶片可溶性糖含量和蔗糖磷酸合成酶(SPS)活性高于豫麦49-198,有助于大穗型品种春季分蘖生长需要。主茎与分蘖间比较,以上糖氮代谢指标均表现为主茎>蘖Ⅰ>蘖Ⅱ,且随分蘖时期进行茎蘖间差异逐渐增加,兰考矮早八表现更为明显,主茎优势突出。豫麦49-198分蘖Ⅰ碳氮代谢强度占主茎比例相对较高,该分蘖能够成穗,而兰考矮早八两分蘖和豫麦49-198分蘖Ⅱ碳氮代谢强度占主茎比例相对较低,严重影响其分蘖发育成穗。

Under field conditions,two wheat cultivars with different ratio of spikes to tillers were used to study difference of carbon and nitrogen metabolism in leaves between different tillers and main caulis,and its relationships with spike formation of tillers during tillering stage.Result showed that winter wheat variety Lankao Aizao 8 with large spike has relative lower tillers before winter,higher spring tillers,long senescence duration of ineffective tillers and low ratio of spike to tiller.The nitrogen metabolism indicators including nitrogen content,amino acid content,glutamine synthetase（GS） activity of leaves in main caulis and tillers was lower in Lankaoaizao 8 than in Yumai 49-198,which was adverse to panicle-differentiation of tillers for the large spike winter wheat variety.The carbon metabolism indicators such as water-soluble sugar content,sucrose phosphate synthase（SPS） of leaves in main caulis and tillers were higher in Lankaoaizao 8 than in Yumai 49-198,which was beneficial to tiller growth and leaf morphological formation in the large spike winter wheat variety.The above physiological indexes showed significant difference between main caulis and tillers with a order of caulis 〉tillers I 〉tillers Ⅱ,this difference was distinct along with tiller growth and especially,the main caulis superiority was obivious in Lankaoaizao 8.The ratio of tiller I to main caulis for carbon and nitrogen metabolism activity was relative high in Yumai 48-198,and the tiller I could form spike.However,and the ratios of tiller Ⅱ to main caulis in Yumai 49-198 and tiller I and tiller Ⅱ to main caulis in Lankaoaizao 8 were relative low,and these tillers could not form spikes.