【摘要】 本研究以小麦磷效率典型基因型为材料,以磷酸三钙为磷源,以水平分根(同时又是相态分根)试验为基本方法研究了小麦对难溶态磷酸盐的活化、吸收机理.当磷酸三钙置于营养液时,磷高效基因型洛夫林10号的吸钙量为磷低效基因型,“中国春”和80-55的2.7和3.6倍.其磷素净活化、吸收量分别较之高30%和77%.当磷酸三钙置于石英砂中时,两类基因型对钙的吸收或对磷的活化、积累保持着类似的趋势.在这种情况下,“中国春”和80-55都不能完成其生活史,而洛夫林10号则能开花结实.说明大量吸收相伴阳离子,主动活化难溶态磷酸盐是小麦磷高效基因型的基本特点.更多还原

【Abstract】 The mechanism of phosphate mobilized by wheat was studied with the typically efficient or inefficient genotypes grown in split pot experiment. The split pot was composed of two parts. The lower part was a two liter-plastic pot containing two liters of nutrient solution and the upper part was a PVC tube of six cm diameter and eight cm height and with a nylon net bottom. The tube was fixed on the pot lid and held 250 g arenaceous quartz. The lid was drilled a small hole in order to add culture solution and 3 % H2O2 instead of aerating. Two seedlings were planted in the quartz of each tube. Ponnamperuma’s recipe was used for preparing the culture solution. Three treatments of P were designed: (1) without any phosphorus, (2) with 0. 5 g tri-calcium phosphate as the only P source added into the solution and (3) with 0. 5 g tri-calcium phosphate as the only P source added into the quartz. The check(CK) took sodium dihydrogen phosphate as P source and put into the solution. When tri-calcium phosphate was put in the solution, the amount of Ca influxed up by the efficient genotype, Lovrin 10 was 2. 7 and 3. 6 times higher than those of the inefficient ones, Chinese Spring and 80-55 and P mobilized and released by Lovrin 10 was 30% and 77% higher than those of the other two genotypes. When tricalcium phosphate was added in the quartz, the genotypical differences in Ca influx or phosphate mobilization was in the same trend as above. Chinese Spring and 80-55 could not complete their life cycle. However, Lovrin 10 flowered and bore fruit as well. It indicated that absorption of more Ca and active mobilization of phosphate were the basic characters of the efficient genotype, Lovrin 10.更多还原