杂草稻与栽培稻苗期根系形态和生理特性比较

Comparison of Root Morphology and Physiological Characteristics between Weedy and Cultivated Rice

杂草稻较强的抗逆性以及对栽培稻的竞争优势与杂草稻的较快生长速率、较强光能利用率等地上部分生物学特性密切相关,但其根系形态及生理特性对其竞争力和抗逆性的影响鲜有报道。本试验以5个不同地区杂草稻种群为材料,以栽培稻(日本晴)为对照,测定播种后10、20、30 d杂草稻和栽培稻根系形态(总根长、根表面积和根体积等)和根系生理(根系总吸收表面积、活跃吸收表面积和根系氧化力)指标。结果表明,播种后30 d,江苏省5个不同杂草稻种群根系形态生理均高于日本晴,杂草稻各种群的根系总根长、根系总表面积、总体积分别显著高于栽培稻36.02%~91.45%、63.21%~90.02%、61.97%~149.30%;杂草稻各种群的根系总吸收表面积、活跃吸收表面积、根系氧化力分别显著高于栽培稻24.98%~124.43%、42.60%~163.30%、31.95%~67.37%。研究结果揭示了杂草稻在苗期具有较强的根系活性,从根系发育及代谢能力角度进一步阐述了杂草稻的竞争优势和抗逆性机制。

Weedy rice is a troublesome conspecific weed with cultivated rice(Oryza sativa).It has strong resistance to stress as well as competitive advantage with the crop.These traits are attributed to the above-ground biological characteristics such as a faster growth rate and a stronger light energy utilization by weedy rice.However,it remains much yet to be understood that morphology and physiology of root have an influence on competitive and resistance.In this study,we use five weedy rice accessions and cultivated rice(Nipponbare)as a comparison,to investigate weedy and cultivated rice root morphology(root total length,surface area,and volume)and physiology(total absorbing surface area and active absorbing surface area,and oxidation activity)at 10,20 and 30 days sowing.Weedy rice from five selected cities surpassed the crop on root morphology and physiology:root total length,surface area,and volume of all weedy rice groups were significantly higher than that of cultivated rice by 36%~91%,63%~90%and 62%~149%,respectively.Total absorbing surface area,active absorbing surface area and oxidation activity in roots were also significantly higher in weedy than in cultivated rice by 25%~124%,43%~163%and 32%~67%,respectively.The results revealed that weedy rice had strong root activity at the seedling stage,from the perspective of the root development and metabolic capability which explains its strong resistance and the competitive advantage.