极端气候条件下辽宁省晚熟玉米品种的风险性评价

通过2009、2010年不同熟期玉米品种栽培试验和生产调查,对晚熟玉米品种在极端气候条件下的风险性进行对比研究。结果表明,晚熟品种受秋旱的影响更大,而熟期较短的品种可在一定程度上躲避"秋吊"。晚熟品种雌穗分化、散粉抽丝和灌浆期与阴雨季节重叠,长时间重度阴雨天易造成晚熟品种空秆和秃尖,而熟期较短的品种则较早地进入该发育阶段,躲避不利天气的影响。耐密植的中熟、中晚熟品种具有较强的耐荫性,因而保持良好的孕穗和结实能力。品种间的耐荫性差异警示为应对极端的气候条件,加强对品种耐阴性的选育,避免品种单一化或品种间遗传背景相近,从遗传角度积极地规避风险。适时早播可作为该地区抵御此类气象灾害的有效措施。

Risk Assessment of Late-maturity Maize Hybrids under Extreme Climate Conditions in Liaoning Province

Maize hybrids with different maturity periods were grown and investigated during 2009-2010 on different regions of Liaoning province, and compared with risk assessment of late-maturity maize hybrids in extreme climate conditions. The results indicated that late-maturity hybrids were more affected autumn drought than mid-maturity and mid-late-maturity hybrids. The mid-maturity and mid-late-maturity hybrids could avoid drought occurred during the middle of August and early September. Late maturity hybrids encountered continuous overcast and rainy days at the booting stage, anthesis and grain filling stage. Late maturity hybrids were susceptible to severe continuous wet weather resulting in barren stalk and bare tip. While the mid-maturity and mid-late-maturity hybrids entered these growth stages earlier than late maturity, thus avoiding the effects of adversely weather conditions. Mid-maturity and mid-late-maturity hybrids with density-tolerance abilities had stronger shade-enduring abilities and kept good booting and grain filling capabilities. The shade-enduring abilities of different hybrids warned that we should pay much attention to breed shade-enduring hybrids in case of extreme climate conditions. Planters and seminal operators should actively avoid risks genetically, such as enriching genetic diversity and avoiding genetic background similarity. Early sowing in optimum time could be an effective measure to against such extreme climate conditions for maize production.