【作者】 汤天泽；

【导师】 牛应泽；

【作者基本信息】 四川农业大学 ， 作物遗传育种， 2005， 硕士

【摘要】 四川农业大学油菜研究中心2001年首次获得了白菜型油菜与海甘蓝属间杂种,本研究以白菜型雅安黄油菜、海甘蓝及杂种一代为材料,主要进行以下几方面的研究:（1）采用不同化学药物处理柱头,研究白菜型油菜与海甘蓝属间杂交的亲和性:a.利用扫描电镜观察海甘蓝花粉在雅安黄油菜柱头上的萌发过程。b.利用荧光显微镜观察海甘蓝花粉管在雅安黄油菜柱头内的生长。（2）杂种细胞遗传学研究,通过根尖细胞观察,确定杂种染色体条数;通过花粉母细胞观察,了解杂种减数分裂过程。此外,还对杂种花粉生活力进行了鉴定。主要结果如下: 1.赤霉素处理柱头,人工授粉1小时后,有少量花粉粘附于柱头上,授粉后6小时柱头粘合的花粉量达到高峰,平均达52个以上,24小时后粘合量平均为32粒。授粉后3小时后,有个别花粉粒开始萌发,柱头乳突细胞内有少量胼胝质生成,6～8小时为萌发高峰期,平均每个柱头约有4～9个花粉粒萌发,但萌发后的花粉管在柱头上的行为表现异常。个别花粉管能进入乳突细胞,多数则出现扭曲、盘绕、螺旋等异常现象,而不能进入柱头。24小时后,柱头内的花粉管进一步向前生长,少量花粉粒出现部分干瘪,但大部分花粉粒仍处于未萌发状态。表明赤霉素在促进花粉萌发及花粉管生长方面效果明显,在一定程度上能克服属间杂交不亲和。 2.甘氨酸处理柱头,人工授粉后1小时,即有大量的花粉附着在柱头表面,平均达75个,柱头乳突细胞内有大量胼胝质生成,授粉后3～8小时,柱头上粘合的花粉量有所减少,到24小时,柱头上粘合的花粉量平均为57个。授粉后6小时后有个别花粉粒开始萌发,8小时后,平均每个柱头约有1～3个花粉粒萌发,花粉粒周围的乳突细胞内有大量胼胝质生成,未见有花粉管进入柱头。授粉后24小时,在柱头内未曾观察到正在生长的花粉管,多数萌发的花粉管继续在柱头表面生长,但表现异常,出现扭曲、盘绕、螺旋,不能进入柱头。表明甘氨酸在促进花粉与柱头的粘合方面效果明显,但不能有效促进花粉的萌发及花粉管的生长,克服属间杂交不亲和的作用有限。 3.白菜型油菜与海甘蓝属间杂种F₁代染色体数目早期为2n=55。经多代组培无性繁殖后,杂种染色体大量减少,数目降至25～28条间,平均为26条。 4.杂种PMC减数分裂中,平均配对构型为0.06Ⅲ+11.26Ⅱ+3.80Ⅰ,二价体数目变化于8～13之间,以10Ⅱ、11Ⅱ、12Ⅱ的细胞出现频率较高,分别为26.60%,23.91%和30.98%,单价体数目变化于0～8个之间。杂种染色体数目减少,二价体个数较高,更多还原

【Abstract】 An intergeneric hybrid between Brassica chinesis and Crambe abyssinica was obtained by Sichuan agricultural university rapeseed research center. In this paper, Brassica chinesis, Crambe abyssinica and the intergeneric hybrid F₁ were used to study the cross compatibility between the two parents and the cytogenetics studies of the hybrid F₁. Main aspects studied include: （1） Compatible studies by means of treating stigmas of Brassica chinesis with different chemicals: a. Observing of the germination of pollen grains of Crambe abyssinica on the stigmas of B. Chinensis with scanning electron microscope. b. Observing of growth of pollen tubes of Crambe abyssinica in the styles of B. Chinensis by fluorescence microscope. （2） Cytogenetical studies of the hybrid: Observing the chromosome numbers of the hybrid in root tip cells, and PMC meiosis process. In addition, the viability of pollen grains were observed. The main results are the following:With treatment of stigmas with gibberellins, at one hour after hand pollination, a small number of pollen grains could adhere to the stigmas. Six hours later, the number of pollen adhering to stigmas reached the climax, averaged at over 52. Twenty-four hours later, the number of adhering pollens was 32. Three hours later, some pollen grains began to germinate and callose could be seen in papillose cells. Germination climax appeared after 6-8 hours, about 4-9 pollen grains geminated per stigma, one or two pollen tubes could penetrate into the papillose cells, while most pollen tubes failed to penetrate the papillose cells. However, the behavior of pollen tube growth was abnormal, forming twist, coil, screw, etc. Twenty-four hours later, pollen tubes continued to grow and reached the style, a few pollen grains began to shrink, and many still failed to germination. It was indicated that gibberellins had a good effect on germination of pollen grains and growth of pollen tubes.When stigmas were treated with glycin, at one hour after hand pollination, a big amount of pollen grains adhered to the stigmas, averaged at 75, a lot of callose was produced in the stigma papillose cells. At three to eight hours later, the amount of pollen grains adhered to stigmas was reduced. Twenty-four hours later, the amount of pollen grains averaged 57. Six hours later, very few pollen grains were seen germinated. Eight hour later, 1-3 pollen grains could be seen germinated, however, large amount of callose had been produced in thepapillose cells. No pollen tubes penetrated papillose cells and entered the style. Twenty-four hours later, no pollen tubes were seen in the style. In most cases, pollen tubes continued to creep on the stigma. Their behavior was abnormal, producing twist, coil or screw, etc. It was observe that glycin could facilitate pollen grains adhering to stigmas, but not facilitate the germination of pollen grains and the growth of pollen tubes. So effects of glycin were limited in overcoming in- compatibility of intergeneric hybridization in rapeseed.The intergeneric hybrid Fi between Brassica Chinensis and Crambe abyssinica showed a chromosome number of 2n=55 in the early progenies. After several generations of planting and in-vitro propagation by tissue culture, the chromosomes in the intergeneric hybrid were reduced, to about 26, varying from 25 to 28.In the meiosis of PMC in the hybrid, the average configuration of chromosomes was 0.06 III+l 1.26 II+3.80 I .The number of bivalents varied from 8 to 13. The majority of PMC cells showed 1011,11 II or 12II bivalents. The frequencies were 24.58%, 23.91% and 30.98% respectively. The number of univalents varied from 0 to 8. The big decrease of chromosome number in the hybrid and high bivalent number were possibly due to the reasons that chromosome of Crambe abyssinica were mostly eliminated and the chromosomes of Brassica Chinensis remained and were doubled in the hybrid cells. Some cells with triads, chromosome lagging, and chromosome bridges were observed in anaphase II.The viability of pollens of the hybrid F( was 63.04%. It was 98.04% for the normal B.napus reference ZhongShuang 4. It is obvious that the viability of pollen grains of the generic hybrid was markedly lower than that of the normal B.napus cultivar. However, the viabilility of pollens in the intergeneric hybrid was still high. This may be related to the doubling of chromosomes in the hybrid.更多还原