甘蓝型油菜不同磷效率品种苗期根系生长及磷营养的差异

对甘蓝型油菜磷高效品种 970 81和磷低效品种 97029苗期根系生长状况和体内无机磷含量及酸性磷酸酯酶活性进行了比较。结果表明 ,磷高效品种的主根长 ,根体积、根 /冠比及根系活力受缺磷影响均比低效品种降低9 3、2 1.9、10 .9、7.8个百分点 ,表现出根系良好的适应性。在缺磷条件下 ,2个品种各部位无机磷含量都有所降低 ,而酸性磷酸酯酶活性则增加。其中磷低效品种 970 2 9各部位无机磷含量降低幅度较大 ,酶活性增长较快 ,表明其根系吸收能力较差 ,体内有机磷分解的程度高 ,苗期即需通过再利用来维持其基本生长 ,使后期的生长失去保障。磷高效品种 970 81各部位无机磷所受影响较小 ,酶活性增长较少 ,根系衰老较慢 ,再利用程度小 ,后期生长潜力大。

The difference of root system growth and P nutrition in the seedlings of rape cultivars with different P-efficiency

Although oil rape (Brassica napus) is generally sensitive to P deficiency,there are still extensive genotypic differences between various cultivars. So, research on its physiological mechanism is helpful to instruct production of rape. Effect of phosphorus on root parameters, inorganic P and acid phosphatase (APase) of two typical rape cultivars 97029 and 97081 were studied under solution culture. Results showed that efficient cultivar 97081 has 9.3%,21.9%,10.9%,7.8% of higher main root length, root volume ,root/top and root activity than inefficient 97029 under P deficiency. That means the root conformation of 97081 is available to absorb more P from soil than 97029.With the lowering of P in medium, inorganic P would decrease but APase activity increase in each organ of both cultivars. However, significant genotypic differences of them can still be found, under same P supply,97081 can keep much higher inorganic P, especially in new leaves; as far as the activity of APase is concerned,97081 changed in a smaller range. That is to say, root of 97081 weakened more slowly to keep better absorption capability and more potential for seed yield, but 97029 couldn't.