论文标题:西瓜多倍体诱导及倍性鉴定的研究
Studies on the Ployploid Induction and Determination of Citrullus Lanatus (Thumb.) Matsum & Nakai
论文作者
论文导师 汪李平,论文学位 硕士,论文专业 蔬菜学
论文单位 华中农业大学,点击次数 11,论文页数 53页File Size3777K
2007-05-01论文免费下载 http://paper.dic123.com/lunwen_106400527/
Citrullus lanatus;; colchicines;; tetraploidy;; inducement;; ploidy determination
西瓜加倍研究具有十分重要的理论意义和经济价值。本试验对秋水仙素诱导西瓜染色体加倍方法进行了初步探讨。并研究了西瓜多倍体鉴定方法及不同倍性的性状比较。试验结果如下： 1．研究了秋水仙素浓度(0.1％，0.2％，0.3％，0.4％)和浸芽时间对西瓜诱导多倍体的影响。结果表明，随浓度的升高出苗率和成株率均出现下降。“0513”、“0517”和“0526”的变异总数分别为4、14和6株。当浸芽12h且秋水仙素浓度为0.1％时，“0513”、“0517”和“0526”的诱导率分别达到2.4％、3.6％和2.7％。 2．研究了上述秋水仙素浓度和浸种时间对西瓜诱导多倍体的影响。结果表明，随秋水仙素浓度的升高发芽率先升高后降低，而胚芽增粗率增大。随浸种时间的增加，发芽率和成活率也出现了不同程度的降低。“0517”和“0525”的变异总植株数分别是20和5株，当秋水仙素浓度为0.1％浸种24h时，“0517”和“0525”的诱导率分别达到4.0％和2.0％。诱导效果最好。 3．研究了上述秋水仙素浓度滴苗对西瓜诱导多倍体的影响。结果表明，随秋水仙素浓度的升高，死亡率均逐渐升高。“0526”、“0515”和“0513”的变异总植株数分别是12、9和3株，当秋水仙素浓度为0.3％时，“0526”、“0515”和“0513”的诱导率分别为5.1％、2.5％和1.9％。 4．西瓜二倍体和多倍体的倍性鉴定采用直接(染色体计数)和间接(DNA流式细胞仪，气孔大小，保卫细胞中叶绿体数目和形态学观察)法。结果表明，染色体计数操作过程麻烦，但切实有效。形态学观察需要很长时间，并不能作为倍性鉴定的唯一标准。DNA流式细胞仪价格昂贵，但可较早的鉴别西瓜的倍性。而用测定气孔和叶绿体的方法简单，更小的劳动量，因此被认为是实际可供选择的方法。二倍体的气孔长度是22.6μm，保卫细胞中叶绿体数目为9.7，而四倍体相应值分别是30.8μm，18.9。 5．通过秋水仙素诱导获得的四倍体品种与二倍体在雄花、种子、果实和品质性状的比较。四倍体具有更大的叶面积(350.1 cm~2)和更高的叶绿素含量(48.7)而叶绿素荧光参数基本相等。与二倍体比较，在四倍体中雄花器官表现更大，果实的大小、中心果肉可溶性固形物含量和近皮果肉可溶性固形物含量相似。二倍体和四倍体的种子千粒重分别是35.3和67.3g，四倍体单瓜中发育成熟的平均种子数为28.4粒。
Studies on the polypliod induction of watermelon has not only theory significancebut economic value extremely. The methods with induced watermelon by colchicinewas discussed preliminarily in this paper. The methods of ploidy determination andcomparison of different polypliod were investigated. The results are as fellowing: 1. Effects of the colchicine concentrations (0.1%, 0.2%, 0.3%, 0.4%) and the timeof soaking buds induced the ployploid watermelon were investigated. The resultshowed that germination rate and survival rate appeared dropping as colchicineconcentrations hoisted. The total number of variation of "0513"、"0517" and "0526"is 4, 14 and 6 respectively. With soaking buds 12 hours and the colchicines density of0.1%, The variation rate of "0513", "0517" and "0526" is 2.4%, 3.6% and 2.7%respectively. 2. Effects of the above colchicine concentrations and the time of soaking seedsinduced ployploid watermelon were investigated. The result indicated that ascolchicine concentrations hoisted, germination rate increased at first but reduced then,plumule increased rate always depressed. With the time of soaking seeds increased,germination rate and survival rate also appeared reducing. The number of variationtotal of "0517" and "0525" is 20 and 5 respectively. With the time of soaking seeds24 hours and the colchicine concentrations of 0.1%, The variation rate of "0517" and"0525" is 4.0% and 2.0% respectively. 3. Effects of the above colchicine concentrations dropped seedling induced theployploid watermelon were investigated. The result indicated that death rate graduallyincreased as colchicine concentrations hoisted. The total number of variation of"0526"、"0515" and "0513" is 12, 9 and 3 respectively. With the colchicineconcentrations of 0.3%, the variation rate of "0513", "0517" and "0526" is 5.1%,2.5% and 1.9% respectively. 4. Direct (chromosome counting) and indirect (flow cytometry, stomatal size,chloroplast number of the guard cells and morphological observations) methods weretested in order to determine the ploidy levels of tetraploid and diploid watermelon. Theresults revealed that while counting chromosomes is cumbersome, but practical waseffective. Producing plants for morphological observations requires a long time andcannot take the only standard of ployploid determination. Although flow cytometry isexpensive, it can earlier determinated the ployploid of watermelon. On the other hand,measurement of stomata and chloroplast counting methods are simple to use are less labour intensive and hence can be considered a practical alternative to the others. Thedata for the stomata in the diploids were length, 22.6μm; and number of chloroplasts ofthe guard cells, 9.7 and in the tetraploids they were 30.8μm and 18.9, respectively. 5. Tetraploid watermelon lines developed by colchicine treatments were comparedwith their diploid counterpart for plant, flower, fruit, seed and qualitative characteristics.Tetraploid genotypes attained statistically higher leaf area (350.1 cm~2) and chlorophyllcontent (48.7) while chlorophyll fluorescence was similar to their corresponding diploid.Staminate flower organs (the thick and length pedicel, anther, the length and width ofpetals) were larger in tetraploid plants. Fruit weight and solid solubility content in bothploidy fruits was similar. The weight of one thousand seeds in fruits varied significantlyand averaged 35.3 and 67.3 g in diploid and tetraploid fruits, respectively. Tetraploidgenotypes yielded lower number of seed was 28.4 per fruit.
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