【作者】 娄方芳；

【导师】 赵林森； 李宗艳；

【作者基本信息】 西南林学院 ， 园林植物与观赏园艺， 2008， 硕士

【摘要】 黄牡丹(Paeonia lutea Delavay ex Franch)是我国西南特有的野生牡丹,是国家三级保护植物,属于濒危物种;作为种质资源黄牡丹在新品种培育以及药用方面也具重要价值。迄今为止关于黄牡丹的研究主要集中在系统分类、染色体、孢粉学等有限的领域;对黄牡丹种子生理学的研究偶见报道;而对其抗旱性的研究至今未见报道。为了对野生黄牡丹进行有效保护与利用,开展其繁殖生物学以及抗旱生理、生态学方面的相关研究显得非常必要和迫切。开展对黄牡丹种子休眠与萌发特性的研究,有助于我们对其种子生理有更全面的了解,同时探求黄牡丹种子繁殖的有效途径,为野生黄牡丹种质资源的保护提供参考。另外,通过对不同黄牡丹居群的抗旱性进行研究,除了有助于了解其抗旱生理方面的特点,同时还可得到不同居群黄牡丹之间的抗旱性差异,为黄牡丹资源保护提供帮助,也可为优良牡丹品种的选育提供一定的理论依据。本文包括两部分试验:(1)种子处理与萌发试验:通过在不同温度条件下,用不同处理方法对昆明西山野生黄牡丹居群种子进行生根和发芽试验;(2)模拟土壤干旱试验:利用土壤干旱处理法中的控水法控制盆栽牡丹苗木的土壤含水量;通过实验室测定苗木相同部位叶片的相对含水量、叶绿素含量、相对电导率、脯氨酸含量及丙二醛含量的变化情况等部分生理生化指标间接鉴定和评价昆明西山居群、玉溪梁王山居群和大理苍山居群黄牡丹的抗旱性差异。两个部分试验结果分别如下:(1)对黄牡丹种子的休眠与萌发特性试验表明:1) 200㎎/L GA3溶液浸泡24h处理、挫伤种脐处种皮与50℃温水浸种三种处理方法对黄牡丹种子胚根的生长都有促进作用;其促根生长的效果从高到低依次为200㎎/L GA3溶液浸泡>种皮挫伤>温水浸泡。2) GA3溶液浸泡能打破黄牡丹种子上胚轴休眠,促进生根种子提前发芽,尤其是对根长超过3㎝的种子发芽更为有效。3)单纯的5℃低温条件不能有效打破黄牡丹种子的上胚轴休眠;15℃是野生黄牡丹种子生根和发芽都比较适合的温度条件。(2)模拟土壤干旱条件的抗旱性试验表明:1)在控水过程中,各居群幼苗盆栽土壤含水量都呈下降趋势:即干旱的前6d土壤含水量下降得比较剧烈;随着干旱胁迫的不断加重,土壤含水量下降的程度趋于平缓。随着土壤干旱程度加剧,叶片含水量急剧下降。三个居群苗木叶片含水量下降程度由强到弱是:大理苍山﹥玉溪梁王山﹥昆明西山。2)在整个控水过程中,三个居群苗木的叶绿素含量都呈下降趋势。从控水第6d开始,各居群苗木叶绿素含量下降的幅度增大,且各居群间下降的幅度呈现较大的差异;叶绿素变幅由大到小的排序为:大理苍山居群、玉溪梁王山居群、昆明西山居群。3)随着盆栽土壤干旱程度加剧,三个居群黄牡丹幼苗的相对电导率都呈上升趋势。在干旱达到8d和10d后,三个居群的相对电导率均急剧增加,增幅排序从大到小依次为:大理苍山居群、玉溪梁王山居群、昆明西山居群。4)三个居群黄牡丹幼苗的脯氨酸含量随着干旱加剧都有所增加。到了干旱第10 d,昆明西山居群的脯氨酸含量约是对照的16倍;玉溪梁王山居群的脯氨酸含量是对照的15倍;大理苍山居群的脯氨酸含量是对照的12.5倍。5)三个居群黄牡丹幼苗的丙二醛含量也都随着土壤干旱程度的提高呈上升趋势。干旱第8d之后丙二醛含量变化较明显,变幅由大到小依次为大理苍山居群、玉溪梁王山居群、昆明西山居群。在干旱第10d,大理苍山居群的比对照增加了47.09%;玉溪梁王山居群的与对照相比增加了41.68%;昆明西山居群的丙二醛含量与对照相比增加了37.17%。6)运用方差分析和主成分分析探讨上述各项因子变化的内在相互关系发现:所测定的生理指标中与昆明西山居群幼苗抗旱性能密切相关的有脯氨酸含量和相对电导率;与玉溪梁王山和大理苍山居群幼苗抗旱性密切相关的生理指标包括脯氨酸含量、叶绿素b。因此可以将这些指标作为黄牡丹抗旱性研究的测定和评价指标。7)采用坐标综合评定法和模糊数学的隶属函数评定法对三个居群的抗旱能力评定结果相同,即三个居群抗旱能力由强到弱依次是:昆明西山﹥玉溪梁王山﹥大理苍山。本试验研究发现三个居群黄牡丹的抗旱能力有所不同,建议在对不同居群黄牡丹实施保护时应该根据其自身特点选择适当的保护策略。对于抗旱性较弱的居群,应加大保护力度;在人工迁地保护时应根据其抗旱能力大小选择适宜的生境;在培植以黄牡丹为亲本的牡丹新品种时,应优先选择抗旱能力较强的居群,从而培养出美观、耐旱的优良品种。更多还原

【Abstract】 Paeonia lutea Delavay ex Franch is a wild peony species indigenous to southwest of china. Being an endanged species, it is listed as a third grade national protected species in china. P. lutea has very important germplasm resource value for new variety breeding and for medicinal purpose. The researches on P. lutea so far have been mostly concentrated in taxonomic classification, chromosome, palynology and some other limited fields. Few of studies were related to its seed physiology, whereas there was not any research report found about drought resistance of this species. So it is essential and urgent to do some researches on its reproductive biology, drought resistant physiology and ecology for this endanged species in terms of appropriate conservation and utilization.Conducting studies on seed dormancy and germination characteristics of P. lutea would be helpful to understanding better its seed physiology, exploring effective approaches for its seeding reproduction, and providing the germplasm conservation of this endanged specis with theoretical and practical references. Carrying out studies on drought resistant characteristics of P. lutea populations from different habitats would be benefitial to understanding its related physiological properties and the difference in this aspect among varied populations so as to provide germplasm resource protection and superior cultivar breeding with guidance.Two experiments were conducted: (1) Seed treatment and germination experiment: rooting and germination experiments were conducted with the seeds collected from wild P. lutea population in the Xishan Mount of Kunming City under different temperature conditions after the seed samples having been treated with different ways; (2) Simulating soil drought experiment: different soil drought statuses were simulated by irrigation control for potted P. lutea plants, and the indexes of lelf water content, chlorophyll content, the change of relative electrical conductivity, contents of proline (Pro) and melondiadehyde (MDA) were mensured together with soil water content in order to evaluate indirectly and appraise the difference in drought resistant capacity among Cangshan Mountains population in Dali, Liangwang Mount population in Yuxi and the Xishan Mount population in Kunming; the results obtained from the two experiments are as follows:(1)The following conclusions were drawn from seed treatment and germination experiment:1) Soaking the seeds in solution of 200㎎/L GA3 for 24h, contusing the testa around hilum and soaking the seeds in 50℃water could all improve the radicle growth, and the effectiveness order was 200㎎/L GA3 solution soaking >testa contusing >50℃water soaking.2) Soaking the seeds with 200㎎/L GA3 solution could break epicotyl dormancy of the rooted seeds and enhance the germination, and the effect was even better on seeds with radicles longer than 3cm.3) Only the 5℃low temperature could not effectively break epicotyl dormancy of the rooted seeds. 15℃temperature was comparatively appropriate for both radicle growth and seed germination of P. lutea.(2)The following conclusions were drawn from the simulating soil drought experiment:1) Water content of the pot planting soil dropped along with the drought process. It dropped dramatically within the 6 days, and then slowed down when the soil became very dry. Seedling leaf water content decreased obviously with the soil desiccation, and the leaf water content declining range order of the three populations was the Cangshan Mountains population in Dali﹥the Liangwang Mount population in Yuxi﹥the Xishan Mount population in Kunming.2) In the entire process of drought stress, chlorophyll content of all the three populations declined gradually. The decline became significant after the 6th day, while there was great difference in the reduction amplitude among the three populations. The biggest reduction happened to the Cangshan Mountains population in Dali , followed by Liangwang Mount population in Yuxi, and the Xishan Mount population in Kunming.3) With the aggravation of drought stress in the soil, all the relative electrical conductivity value of seedlings of the three populations increased. The increment of the value became obviousy after the 8th day, and the order of increase amplitude was the Cangshan Mountains population in Dali, the Liangwang Mount population in Yuxi, and the Xishan Mount population in Kunming. 4)Proline (Pro) content of all the seedlings inceased along with the aggravation of drought stress. Compared with the CK of each population, the proline content of the Xishan Mount population in Kunming increased by 15 times; the value of Liangwang Mount population in Yuxi increased by 14 times, and the value of Cangshan Mountains population in Dali increased by 11.5 times.5) Melondiadehyde (MDA) content of all the three populations increased along with the aggravation of drought stress in the soil. The increment became siginificant after the 8th day of drought stress, and the change amplitude order from the largest to the least was the Cangshan Mountains population in Dali, the Liangwang Mount population in Yuxi, and the Xishan Mount population in Kunming. By the 10th day of the drought stress, MDA content of the of Cangshan Mountains population in Dali increased by 47.09% compared to the CK group, the value of the Liangwang Mount population in Yuxi increased by 41.68%, and the MDA content of Xishan Mount population in Kunming increased by 37.17% versus to its own contrast.6) It was indicated by the variance analysis and the main components analysis on the inherent correlations among above physiological indices that: The proline content and the value of relative electrical conductivity indices of the Xishan Mount population in Kunming were closely related to the drought resistance characters. Indices of proline content and chlorophyll b content of both Liangwang Mount population in Yuxi and Cangshan Mountains population in Dali were closely related to their drought resistance properties. So it was proposed that these indices could be used for eualuating drought resistant capacity for P. lutea.7) The same results were obtained by the Coordinate Comprehensive Evaluation and the Affiliated Equation Evaluation on each physiological index of the three P. lutea populations, i.e., the drought-resistant capacity of the three populations was in this order: the Xishan Mount population in Kunming﹥the Liangwang Mount population in Yuxi﹥the Cangshan Mountains population in Dali.It was showed by the experiments that there was diffenrence in drought resisitant capacity among the three P. lutea populations, indicating that appropriate conservation strategies concerning of the intrinsic charactersitics should be taken for different populations. Greater efforts should be done to protect the population with weaker drought reisistance. Suitable habitats should be selected for ex situ conservation according to its drought resistant capacity. The population with stronger drought resistance should be applied in priority as parental materials in the process of P. lutea cultivar breeding, so that the new vatieties could be drought resistant beside its beauty and other superior traits.更多还原