【作者】 王颖；

【导师】 穆春生；

【作者基本信息】 东北师范大学 ， 生态学， 2008， 博士

【摘要】 广布野豌豆(Vicia cracca)是多年生的豆科牧草,是中国北部的饲料作物。它是一种高品质的野生牧草,可以作为饲料、干草、青贮饲料。但由于广布野豌豆在种子收获时,存在裂荚现象,裂荚导致种子损失给种子生产带来一定的困难。提早收获虽可以在一定程度上减少种子损失,但会造成减产及降低种子品质,收获过晚会导致种子减产。很多农艺学的方法曾被应用在实际生产中,但是这些方法很难应用到生产中或在实际生产中这些方法不能有效的抑制裂荚。因此很多研究者为了减少种子损失注重种子适宜收获时间的研究。所以本文的研究目的是进行广布野豌豆荚果和种子的发育动态研究进而确定适宜的种子收获时间,解决广布野豌豆在种子生产上存在的问题。实验地点位于中国松嫩草地生态研究站(北纬44°45′,东经123°45′);广布野豌豆2003年种植,于2005～2007年间进行田间和室内实验。于8月初——盛花期标记完全开放的花朵,标记的花朵每3 d取样一次直到盛花后第42 d。2005～2006年进行荚果和种子的形态学特征、生理学特征和种子品质的测定;2006年收获的种子进行抗盐碱性测定;2005～2006年于种子成熟期,进行裂荚率及与裂荚相关的各项指标的测定;2007年进行种子的生理学指标及种子硬实率的测定。研究结果如下:1.不同取样时期广布野豌豆荚果和种子发育动态实验结果表明,荚果和种子的形态学指标,颜色和大小在种子失去绿色后(盛花后36～42 d)与其他取样时期明显不同;盛花后30～42 d种子干重和千粒重达到最大,盛花后36～42 d荚皮和种子含水量达到最小;标准发芽实验、抗衰老实验、抗冷实验结果显示盛花后33～42 d种子的发芽时间最短、种子发芽率、发芽速率、胚芽长及活力指数均达到最大值;电导率实验结果显示盛花后27～42 d种子的电导率值最小。2.不同取样时期广布野豌豆种子的抗逆实验结果显示,盛花后33～42 d种子的发芽指标,发芽率、发芽势、发芽速率、胚根长、活力指数显著大于其他取样时期种子的各项发芽指标,抗逆性以盛花后33～42 d种子的抗逆性为最佳;相同取样时期广布野豌豆种子的抗盐能力大于抗碱能力。3.不同取样时期广布野豌豆种子硬实率的测定结果显示,盛花后36 d的种子开始出现硬实现象,此时种子形态学指标和生理学指标都明显区别于其他时期种子的形态学指标和生理学指标,硬实率与种子的含水量呈显著的负相关关系;阴干后的种子盛花后24 d开始出现硬实,硬实率与种子的含水量也呈显著的负相关关系。4.不同取样时期广布野豌豆裂荚研究结果显示,一天当中,裂荚率从6:00～8:00及16:00～18:00为0,最大裂荚率发生在12:00～14:00。当阳光充足时,裂荚率与空气湿度和荚皮含水量呈显著的负相关关系,与空气温度和荚表面温度呈显著的正相关关系;当阴天时裂荚率很小,与各因素间无相关关系。但偏相关分析结果显示,裂荚率与环境因素无相关性。综上所述,广布野豌豆精确的种子适宜收获时间为盛花后36～42 d。一天当中广布野豌豆种子适宜收获时间,阳光充足时为6:00～8:00及16:00～18:00,当阴天时全天都可以收获种子。荚果和种子颜色及大小是种子收获快速、准确的指标。荚皮和种子含水量相对干重和千粒重是比较精确的指标;品质及抗逆性测定实验中的发芽时间、发芽率、发芽速率、胚芽长、胚根长及活力指数等不能作为种子收获的适宜且精确的指标;电导率和积温不能作为种子收获适宜且精确的指标。更多还原

【Abstract】 Vicia cracca is a perennial legume plant and one of the most common fodder plants in northern China. It is a wild high-quality forage widely grown mostly for hay, green forage, silage and grain. However, V. cracca seed production is a major problem because of pod shatter at plant maturity. Pods are fragile at harvest time and seed loss can negatively impact yield. Harvesting too early may result in low yield and poor seed quality, whereas harvesting too late may result in shattering and reduced seed yield. Many agriculture methods have been used to apply in production. Unfortunately, many of these methods are difficult to apply in production, while in others seed loss is not effectively prevented. Researchers have focused on determining optimum harvest time to avoid seed loss. Thus the aim of this research was to study the development of pod and seed and determine the optimum harvest time of Vicia cracca to resolve the problem in production.The experiment was conducted at Ecosystem Field Station of the Institute of Grassland Science at Songnen Grassland in China (44°40′N 123°44′E, 167 m above sea level). V. cracca plants were sown in 2003. Field and laboratory experiments were conducted from 2005 to 2007. Flowers were tagged in early August at peak anthesis. Tagged pods were harvested at 3-day intervals beginning 9 days after peak anthesis (DAPA) and continuing until 42 DAPA. Pod and seed morphological characters, pod and seed physiological characters and seed quality were determined from 2005 to 2006. Seeds were harvested and evaluated seed salt and alkaline resistance in 2006; The rate of pod shatter was recorded and measure the indexes related to pod shatter in 2005 and 2006 during seed maturity; In 2007, we measured the physiology indexes and the rate of hardseededness. The results were showed as followed:1. The result of the development of pod and seed of V. cracca showed that pod and seed color and sizes were significant different from other sampling dates from they loss green (from 36 to 42 DAPA). Seed dry weight and thousand seed dry weight reached the highest from 30 to 42 DAPA. Pod and seed moisture contents were lowest from 33 to 42 DAPA. The results of standard germination test, accelerated aging test and cold test showed that the percentage germination, germination rate, embryo length and germination vigor were highest from 33 to 42 DAPA. The electrical conductivity was lowest from 27 to 42 DAPA.2. The result of adversity test showed that percentage germination, germinatin energy, germination rate, radical length and germination vigor were higher from 33 to 42 DAPA than other sampling dates. Adversity resistance was higher from 33 to 42 DAPA than other sampling dates. And the seed of the same sampling date in salt resistance was higher than alkaline resistance;3. The result of the rate of hardseededness in different sampling dates showed that hardseeded seeds occurred at 36 DAPA. The morphological and physiological indexes were significant different from other sampling dates. A strong negative correlation was found between seed moisture content and percentage of hard seed during seed development. The hardseeded seed occurred at 24 DAPA and a strong negative correlation was found too between seed moisture content and percentage of hard seed when seed dried for about 1 month.4. The results of the pod shatter in different sampling dates during seed maturity showed that the rate of pod shatter was 0 from 6:00 to 8:00 and from 16:00 to 18:00 in one sunshiny day. The rate of pod shatter was nearly 0 in the whole cloudy day. A strong negative correlation was found between the rate of pod shatter and humidity, pod moisture content. A strong positive correlation was found between the rate of pod shatter and air temperature, pod wall temperature. However, there was no correlation between the rate of pod shatter and other indexes in a cloudy day. The partial correlation result showed that there was no correlation between the rate of pod shatter and the indexes of circumstance factors.The optimum harvest time of V. cracca in different sampling dates was from 36 to 42 DAPA. The optimum harvest time of V. cracca during harvest time was 6:00～8:00 and 16:00～18:00 in one sunshiny day and every time was optimum in a cloudy day.Pod and seed color and sizes could be dependable and rapid indicators providing a simple way for seed producers to judge optimal harvest time. Pod and seed moisture contents were more accurate than seed dry weight and thousand seed weight relatively. Germination time, percentage germination, germination rate, embryo length and germination vigor could not be the accurate indicators. Electrical conductivity and growing degree days could not be the accurate indicators too.更多还原