【作者】 许凤芹；

【导师】 刘桂茹； 杨学举；

【作者基本信息】 河北农业大学 ， 作物遗传育种， 2005， 硕士

【摘要】 小麦是重要的粮食作物之一,然而,世界各地因程度不同的干旱所导致的小麦减产十分严重。目前,干旱已成为影响我国小麦产量的最主要因子。因此,选育抗旱性强的品种是干旱和半干旱地区挖掘小麦产潜力的迫切问题,利用组织培养筛选抗旱无性系为抗旱育种提供了一种有效捷径。到目前为止,在细胞水平上鉴定品种抗旱性尚缺乏具体而系统的方法。本研究旨在利用组织培养确定适合快速鉴定小麦品种抗旱性的筛选剂(PEG)最适浓度及适宜的添加时期,为小麦抗旱无性系筛选及资源鉴定提供理论依据。 本研究将抗旱性不同的4个小麦品种的花药和幼胚直接接种在含有不同PEG浓度的固体培养基中诱导愈伤组织,并分化植株。通过测定幼胚愈伤组织的生长曲线、相对生长量,幼胚愈伤组织及再生植株的SOD活性、POD活性、MDA含量等生化指标、统计出愈率和对再生植株农艺性状观察来研究不同抗旱性小麦品种在不同PEG浓度下的差异性,结果表明: (1) 将小麦花药和幼胚直接接种于添加不同浓度PEG的培养基中,小麦品种花药和幼胚出愈率均发生明显变化。1%～5%的PEG能显著提高小麦品种花药出愈率,而对幼胚的作用不明显。在10%的PEG浓度下,抗旱性强的品种花药和幼胚出愈率均显著高于抗旱性弱的品种。15%、20%、25%的PEG极显著的降低小麦品种花药和幼胚的出愈率。 (2) 通过在培养基中添加不同浓度的PEG来模拟不同程度的水分胁迫,测定抗旱性不同的小麦品种幼胚愈伤组织的生长曲线,结果表明,水分胁迫使愈伤组织的生长受到抑制,并随水分胁迫强度的加大,抑制程度逐渐加深。对愈伤组织的生长抑制程度抗旱性强的品种低于抗旱性弱的品种。 (3) 在培养基中加入不同浓度的PEG,小麦品种幼胚愈伤组织的相对生长量均发生显著变化。在培养基中添加1%、3%的PEG与对照之间愈伤组织相对生长量无显著性差异。在培养基中添加5%、10%、15%、20%、25%的PEG与对照之间愈伤组织相对生长量有极显著性差异。抗旱性强的花84、晋麦33在添加10%PEG的培养基中与对照之间愈伤组织相对生长量无显著性差异,而抗旱性弱的温麦6、冀麦7在添加10%PEG的培养基中与对照之间愈伤组织相对生长量有显著差异。所以,小麦品种愈伤组织相对生长量在添加10%PEG培养基中与对照之间的差异显著性可以作为抗旱性鉴定、筛选的一个指标。 (4) 通过不同浓度PEG的作用效果以及幼胚愈伤组织主要生化指标分析表明,利用组织培养鉴定小麦品种抗旱性时,添加10%PEG的培养基是适合的高渗培养基。SOD和MDA是较理想的生化评定指标。 (5) 小麦幼胚愈伤组织经低浓度的PEG长时间诱导继代培养(45d),在含有原浓度PEG的培养基中分化的植株比转到对照上分化的植株SOD活性、MDA含量明显增加,抗旱性强的品种SOD活性增加幅度高于抗旱性弱的品种;抗旱性弱的品种MDA含量增加幅度高于抗旱性强的品种。更多还原

【Abstract】 The wheat is one of the most important crops, however, the yield of wheat reduced very serious in world-wide area because of the drought in different degree. The drought has become the most important factor that affect the wheat yield in our country at the present time. Therefore, breeding and selecting the drought resistance varieties is an urgent problem for scoop out the potential fertility of wheat in drought and half-drought area. It is a kind of valid shortcut to make use of tissue culture to select drought resistance asexuality line for drought resistance genetic and breeding. However, there is still lack of specific method to authenticate the drought resistance varieties line in cell level. This research aim is making use of the tissue culture to certain the most suitable concentration of the chemical reagent(polyethylene glycol) and the period when the chemical reagent be put into the culture media for drought resistance varieties authentication of wheat quickly. Then offering proof for selecting drought resistance asexuality line and resources authentication of wheat.In this research there are four varieties of anther and immature embryo of wheat were inoculated in solid medium directly containing different concentration of PEG to induce callus and regenerate the plant. Using the weighing method to built-up growth curve and measure the relative weight of callus, measuring the SOD activity, POD activity and MDA content of callus induced from immature embryo ,further more, statistics of initiating rates and observing the agricultural characters of the regenerated plant to study the difference among the different varieties of wheat growing in the solid media containing different concentration of PEG.(1) If anther and immature embryo of wheat are inoculated in solid media directly containing different concentration of PEG, their initiating rate will change distinctly. 1%-5% PEG can increases the initiating rate of anther obviously, but the function is unconspicuous to immature embryo. Under the concentration of 10% PEG, the varieties of anther and immature embryo with high drought resistance have higher initiating rates than the low drought resistance varieties. 15%,20%,25% PEG can lower the initiating rate of anther and immature embryo sharply.(2) Using the different concentration of PEG to imitate the different degree of water更多还原