小麦植物铁载体分泌基因的染色体定位

Chromosomal Location of Genes Controlling the Rate ofPhytosiderophore Release in Hexploidy Wheat

采用室内控制生长条件的营养液培养技术，通过检测缺铁条件下20个中国春的Hope染色体代换系（缺4D染色体代换系）及其亲本中国春和Hope小麦植物铁载体分泌的动态变化规律以及植物铁载体（简写为PS）分泌高峰期内5次测定值的汇总资料，对六倍体小麦PS分泌基因进行染色体定位。PS分泌率通过根分泌物对新形成的Fe（OH）3的活化能力进行测定，在缺铁症出现时每隔2、3天测定1次，随着缺铁失绿症严重程度的增加，PS分泌率呈现迅速增高再逐渐降低的趋势，不同基因型小麦之间PS分泌率存在明显的差异，而且中国春的同分泌率一直高于Hope。在20个染色体代换系中，1A、3A、4A、5A、6A、3B、4B、2D、3D与7D等10条染色体代换系的PS分泌率明显低于中国春，说明Hope的这些染色体代换掉相应的中国春染色体后引起了中国春PS分泌率的显著变化。因此这些染色体具有与PS分泌率有关的基因，而其他染色体与之无关。

The chromosomal location of genes controlling the rate of phytosiderophore (PS)release in hexploidy wheat (Triticum aestivum L.) under iron deficiency was studied in20 cv. Hope chromosome substitution lines of Chinese Spring {lacking [4D(4D)]},chromosome donor Hope and chromosome recipient Chinese Spring grown undercontrolled environmental conditions in nutrient solution for 35 days. PS release rateswere determined at two or three day intervals after onset of Fe deficiency symptomsby the measurement of iron mobilizing capacity of root exudates from freshlyprecipitated FeⅢ hydroxide. At the beginning, PS release rapdly increased with theseverity of the Fe deficiency induced chlorosis and then decreased gradually. Thedifferences of PS release among genotypes were also observed. During this experimentChinese Spring always had a higher PS release rate than Hope. In the case of thetwenty subshitution lines, every PS release rate from 1A, 3A, 4A, 5A, 6A, 3B, 4B,2D 3D and 7D chromosom substitution lines was obviously less than that fromChinese Spring, which indicated that the rate of PS release from Chinese Spring hadbeen significanhy changed after these chromosomes of Chinese Spring were replacedrespechvely with the cormsponding chromosomes of Hop. Therefore, thesechromosomes, 1A, 3A, 4A, 5A, 6A, 3B, 4B, 2D 3D and 7D were associated withthe release rate of PS from roots of iron deficiency sbessed Chinese Spring, while theothers were not related to this the.