高寒地区播期对三种裸燕麦品种灌浆特性影响的研究

以青引3号、白燕2号和坝燕3号莜麦为研究对象,在青藏高原地区开展了播期对3种裸燕麦品种灌浆速率及灌浆特性的研究,旨在掌握和了解3种裸燕麦籽粒灌浆特性,为青藏高原地区裸燕麦种子生产提供理论依据。结果表明,3种裸燕麦不同播期籽粒灌浆规律均符合Richards曲线,灌浆进程可划分为前、中和后3个时期,各时期持续时间分别为16~20d、7~9d和4~7d,中期灌浆速率最大,平均1.54g/(d·千粒),分别是前期和后期的2.53和3.23倍。灌浆过程中其干物质积累量(千粒重)呈现"慢-快-慢"的递增变化,籽粒含水量呈现"慢-快-慢"的递减变化,灌浆速率和脱水速率呈现先增后减的变化,平均灌浆速率呈现"降-增-降"的变化。播期对3种裸燕麦灌浆进程无显著影响,但对其千粒重增加影响较大,4月3日播种条件下3种裸燕麦品种较晚7和14d播种的最大灌浆物质积累量平均分别高2.59和4.05g/千粒。不同播期下3种裸燕麦千粒重的增加与灌浆速率呈负相关,而与灌浆持续期呈正相关。千粒重较大的白燕2号莜麦具有较大的灌浆速率,达到1.22g/(d·千粒),千粒重较大的裸燕麦品种通过增加平均灌浆速率来实现物质积累,而与实际灌浆时间关系不大。在青藏高原高寒地区裸燕麦种子中,播期对籽粒灌浆速率和干物质积累量影响较大,选择4月初播种可显著增加裸燕麦干物质积累量,实现高产。

Effect of sowing date and variety on grain-filling in naked oats

To understand the grain-filling characteristics of 3 naked oat (Avena nuda )varieties;Qingyin No.3, Baiyan No.2,Bayan No.3 and to provide technical guidelines for seed production of naked oats in the Qinghai-Tibetan Plateau,the effect of sowing date on grain-filling were assessed.Grain-filling in all 3 varie-ties,irrespective of sowing date,consisted of 3 stages;early,mid and late which fitted a Richards function. Durations of the early,mid and late stages were 16-20 d,7-9 d and 4-7 d,respectively.Maximum rate of grain-filling observed in the mid stage was 1.54 g/d (1000-seeds),2.53 times and 3.23 times that of the early and late stages,respectively.During grain-filling dry-matter accumulation (thousand kernel weight,TKW) was initially slow,rapid in the intermediate stage and slow in the late stage.Conversely,moisture content de-crease followed the same pattern.Sowing date had no effect on grain-filling in any variety,but did influence TKW.The maximum dry matter accumulation rate from the earliest sowing (April 3 rd )was 2.59 g/(1000-seeds)and 4.05 g/(1000-seeds)higher than those in the later sowing dates,7 and 14 d,respectively.The TKW accumulation was negatively correlated with the rate of grain-filling and positively correlated with the du-ration of grain-filling.Baiyan No.2 had the highest TKW and grain-filling rate (1.22 g/d·1000-seeds).It is implied that the higher TKW of the naked oat varieties in this study was more dependent on higher grain-filling rate,and is less dependent on the duration of grain-filling.The results of the study showed that sowing date significantly affected the accumulation of dry matter;sowing in early April in the Qinghai-Tibetan Plateau re-sulted in greater accumulation of dry-matter and higher yield of naked oats.