热研4号王草对不同有机磷活化利用能力的评价

Evaluation on the Capacity of Different Organic Phosphorus Utilization in Reyan No.4 King Grass

本研究以热研4号王草(Pennisetum purpureum×P. glaucum cv. Reyan No. 4)为材料,通过砂培试验评价其对4种有机磷的利用能力。结果表明,王草对三磷酸腺苷(ATP)、二磷酸腺苷(ADP)、一磷酸腺苷(AMP)和6-磷酸葡萄糖(G6P)均具有利用能力,且对磷酸单酯类(AMP和G6P)的利用能力更强。酸性磷酸酶(ACP)活性分析表明,有机磷处理使王草根系内源与分泌的总ACP活性显著增加0.9倍以上,但王草对有机磷的利用能力与根系总ACP活性无相关性。进一步分析发现,王草根系分泌特异ACP活性与不同有机磷处理的植株干重显著正相关,相关系数R^2=0.861。综上所述,本研究发现王草对不同类型有机磷的利用能力主要由其根系分泌的特异ACP活性决定。研究结果可为选育磷高效热带牧草品种提供理论依据。

In this study, Pennisetum purpureum × P. glaucum cv. Reyan No. 4(King grass) was used to investigate the capacity to utilize four types of organic phosphorus(P) in a sand cultivation experiment. The results showed that King grass had different capabilities to mobilize adenosine triphosphate(ATP), adenosine diphosphate(ADP), adenosine monophosphate(AMP), glucose-6-phosphate(G6 P), and more capable of utilizing phosphate monoester(AMP or G6 P)as the sole P source. Analysis of acid phosphatase(ACP) activity showed that total internal-ACP and secreted-ACP activities of roots significantly increased by more than 0.9-fold in organic P treatments. However, correlation between root total ACP activity and capacity to utilize organic P in King grass was not significant. Furthermore, significant positive correlation was found between root specific secreted-ACP activity and plant dry weight in different organic P treatments,with the observed R^2=0.861. Taken together, our results suggest that root specific secreted-ACP activity control organic P utilization in King grass. Our results would provide a theoretical basis for selecting and breeding tropical grass varieties with high P efficiency.