硝酸还原酶活力与作物耐肥性的研究 Ⅲ.北方粳稻品种演变过程中硝酸还原酶活力与品种性状之间的关系

对北方粳稻栽培品种演变过程中品种性状和硝酸还原酶活力变化的研究表明:1)品种性状在演变过程中有了明显的变化,即从大穗高秆向多穗矮秆的方向变化;2)品种抗倒耐肥性变化的总趋势是由弱到强,其硝酸还原酶活力从高到低的变化。这就是说过去老品种大穗高秆,不抗倒不耐肥,硝酸还原酶活力高,而目前推广品种多穗矮秆,抗倒耐肥,硝

STUDIES ON NITRATE REDUCTASE ACTIVITY AND NITROGEN RESPONSE IN CROP PLANTS Ⅲ.THE RELATION OF NITRATE REDUCTASE ACTIVITY WITH CHARACTERS OF CULTIVAR IN THE SUCCESSION OF RICE CULTIVATED IN NORTHERN CHINA

The present study on 17 rice cultivars,which were cultivated in Northern China from early of this century to today,indicated that:1).The characters of cultivars had been changed obviously in the successionof rice,showing a tendancy from big-ear and tall-stalk to multiple-earsand short-stalk.2).The general trend of nitrogen response of cultivars varied towards the cultivars suitable for higher level of nitrogen fertilizer.In reverse,the nitrate reductase activity of cultivars variedtowards lower level,resulting in a close relation with nitrogen response.In general,the cultivars in early period exhibited a big ear and tallstalk,higher nitrate reductase activity,sensitive to lodging and suitablefor lower level of nitrogen fertilizer.The cultivars in late period exhibited multiple ears and a short stalk,lower nitrate reductase activity,resistant to lodging and suitable for higher level of nitrogen fertilizer.The further analysis revealed a significant negative correlation of nitrate reductase activity with the ears/m~2 of cultivar(r=-0.7302~*)and asignificant positive correlation of nitrate reductase activity with theheight of stalk of cultivar(r=+0.6815~*).