结实期土壤水分对水稻产量与品质的影响

Effect of Soil Moisture During Grain Filling on Grain Yield and Quality of Rice

以汕优63(杂交籼稻)和武育粳3号(粳稻)为材料,自抽穗至成熟期,设盆钵内土壤水势5个处理为0(对照)、-15、-30、-45、-60kPa,研究了土壤水分对产量和稻米主要品质性状的影响。结果表明,当汕优63土壤水势为-15kPa和-30kPa、武育粳3号土壤水势为-15kPa时,结实率、千粒重和产量较对照显著增加。结实期土壤水分对稻米的出糙率、精米率、粒长/粒宽、直链淀粉含量和粗蛋白含量无显著影响。汕优63土壤水势为-15kPa和-30kPa处理及武育粳3号土壤水势为-15kPa处理的整精米率与对照无显著差异,垩白米率、垩白度和消减值较对照显著降低,淀粉谱的最高粘度和崩解值则显著增加。汕优63土壤水势为-45kPa和-60kPa处理以及武育粳3号土壤水势为-30kPa、-45kPa和-60kPa的处理的结实率、千粒重、产量、整精米率、胶稠度、碱消值、最高粘度和崩解值较对照显著降低,垩白米率、垩白度和消减值较对照显著增加。建议将土壤水势为-15kPa与-30kPa和-15kPa分别作为汕优63和武育粳3号结实期优质高产节水灌溉的低限土壤水势指标。

Rice cultivars of Shayou 63 （indica hybrid） and Wuyujing 3 （japonica） were used as materials, and were pot-grown. Five treatments, soil water potential at 0, -15, -30, -45, and -60kPa, were conducted from heading to maturity. The grain yields and main indexes of quality were investigated. The results showed that, in comparison with the control, grain-filed percentage, lO00-grain weight and grain yield were signifi cantly higher when soil water potentials were at -15kPa,-30kPa for Shanyou 63 and at -15kPa for Wuyu- jing 3. Soil water potentials, ranged from 0 to -60kPa, had no significant effect on brown rice percentage, milled rice percentage, kernel length/kernel width, am ments of soil water potentials at -15kPa and -30kPa ylose content, and protein content. Under the treatfor Shanyou 63 and at -15kPa for Wuyujing 3, the head rice percentage was not significantly changed, and the chalky grain percentage, chalkiness and setback values were significantly decreased, while peak viscosity and breakdown values were significantly increased when compared with the control. The grain-filed percentage, 1000-grain weight, grain yield, head rice per- centage, gel consistency, alkali spreading values, peak viscosity and breakdown values were significantly reduced, and the chalky grain percentage, chalkiness and setback values were significantly increased when soil water potentials were at -45kPa to-60kPa for Shanyou 63 and at -30kPa to -60kPa for Wuyujing 3. The results suggest that soil water potentials at -15kPa to -30kPa for Shanyou 63 and -15kPa for Wuyujing 3 could be as low-limit indexes for high-yielding and good quality of rice in the water-saving irrigation during the grain filling period.