冬小麦植物铁载体分泌的杂种效应

缺铁是石灰性土壤常见的植物营养问题之一.禾本科植物种或基因型的植物铁载体分泌能力与耐缺铁有关,提高植物铁载体分泌能力是改良缺铁的土壤上植物铁aestivum L.) 3个杂交种及其4个亲本在缺铁营养液中植物铁载体的分泌及杂种的效应.植物铁载体的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.在缺铁条件下,所有基因型都分泌较多的植物铁载体,并且随缺铁症状的发展分泌量增加.杂交种具有对缺铁更敏感的反馈系统,在缺铁条件下,杂交种比亲本分泌铁载体的速度更快、量更高.通过分析杂交种和亲本的关系,认为可以通过对亲本分泌植物铁载体能力和配合力的选择,利用杂种优势来提高小麦铁的利用效率.

Hybrid Effects on the Release of Phytosiderophores in Winter Wheat (Triticum aestivum)

Fe (iron) deficiency is an important nutritional problem particularly in crop plants grown on calcareous soils. Phytosiderophore (PS) release has been suggested to be linked to the ability of graminaceous species and genotypes to overcome Fe-deficiency chlorosis. Thus, enhancing PS release is a critical step to improve Fe nutrition of plants grown on Fe stressed soils. The heterosis of PS release rate in common wheat was studied by analyzing PS release from roots of three hybrids and their four parents grown in Fe-deficiency nutrient solution under controlled environmental conditions. PS release rates were determined at two or three day intervals after onset of Fe-deficiency symptoms by the measurement of Fe mobilizing capacity of root exudates from freshly precipitated FeⅢ hydroxide. High amounts of phytosiderophores were released from the roots of all wheat genotypes under Fe-deficiency, and the amount progressively increased with the development of Fe-deficiency chlorosis. The results revealed that the hybrids had more sensitive feedback systems which secreted more phytosiderop hores under Fe-deficiency than their parents. By analyzing the relationship between each hybrid and its parents, it was also found that the parents should be selected on the basis of the rate of PS release and the combining ability by using the heterosis to improve Fe utilizability of crop plants.