大麦株高近等基因系的磷素利用效率特性分析

为明确大麦株高对磷素利用效率的影响,采用土培盆栽试验,以4对两种遗传背景下的大麦株高近等基因系为材料,设置施磷(P_2O_5:60 mg·kg~(-1)土)和不施磷两种磷处理,于成熟期采样,分析其农艺性状、磷含量、磷素利用效率等差异。结果表明,施磷处理下大麦近等基因系株高、单株产量、单株秸秆干重及收获指数均较不施磷处理增高,高秆大麦的株高、穗长、芒长、产量及收获指数均显著大于矮秆大麦,而其单株秸秆干重小于矮秆大麦。施磷处理下近等基因系根系、秸秆、籽粒磷含量及磷积累量整体高于不施磷处理。不施磷处理下,高秆大麦的秸秆磷含量及磷积累量整体小于矮秆大麦,而其籽粒磷积累量整体大于矮秆大麦,最大高出矮秆大麦89.87%。施磷处理下大麦的根系、秸秆及籽粒磷素利用效率小于不施磷处理,秸秆磷素利用效率变化最大,施磷为不施磷的25%～68%,其中高秆大麦变化幅度大于矮秆大麦。经相关性分析,大麦单株产量与籽粒磷积累量呈显著正相关,与根系磷积累量呈极显著或显著负相关;穗长与秸秆磷利用效率、株高与磷收获指数以及芒长与磷收获指数在施磷和不施磷处理下分别呈显著负相关和正相关。相较于矮秆大麦,高秆大麦在低磷环境下具有更高的收获指数及磷收获指数,说明高秆大麦具有更高的耐低磷特性。因此,在缺磷土壤中选择株高较高的大麦能获得更好的经济效益。

Phosphorus Use Efficiency in Barley Near-Isogenic Lines of Plant Height

This study focused on analyzing the P utilization efficiency(PUE) in near-isogenic lines of plant height of barley,so as to reveal the effect of plant height on PUE. Four pairs of barley plant height near-isogenic lines,which were from two genetic backgrounds,were subjected to a P application of 60 mg P₂O₅·kg^-1 soil and 0 in a pot experiment. Samples were collected at mature stage to analyze their agronomic traits,P content and PUE. Further correlation analysis was performed on these indicators. The results show that tall lines showed higher plant height,panicle length and awn length. The total plant height with P application were greater than that without P treatment,indicating that the application of P could increase the plant height of barley. The straw biomass per plant of dwarf lines were higher than that of the high lines,reaching to a significant level without P treatment. P content and accumulation of roots,straw and grain showed higher tendency with P application than those without P application. The P content and accumulation in straw were generally higher in dwarf lines than in tall lines without P application. The P accumulation in grain of tall lines were 1.15-1.90 times more than that of dwarf lines,the highest can be 89.87% higher.The P content and accumulation in roots and the P content in grain were only significantly different in some near-isogenic lines. It was found that the PUE in different pairs of near-isogenic lines were generally higher under no P application conditions than that under P application condition. The change of straw PUE was the largest,and the PUE of straw with P application was 25%-68% of it without P application.The tall lines changed more than the dwarf lines.The PHI of high lines were generally higher than that of dwarf lines without P application while it was generally lower than that of dwarf lines with P application. The correlation analysis showed that there was a significantly positive correlation between yield per plant and grain P accumulation under different P treatments,and a significant negative correlation between yield per plants and P accumulation in roots. The correlations between panicle length and PUE of straw,plant height and PHI,awn length and PHI all showed a significant negative correlation with P application and a significant positive correlation without P application. When in a low-phosphorus environment,high lines of barley has higher HI and PHI,indicating that high lines of barley distributes relatively more P to the grain under P-deficient conditions,resulting in a relatively higher yield. Therefore,the high lines of plant height near-isogenic lines of barley suit better for low-P stress,and it can get better economic benefits in P-deficient soils.