共查询到20条相似文献，搜索用时 140 毫秒
1.
目前生产上推广应用的多倍体种子主要是包含有二倍体、三倍体及四倍体成份的混倍体(又称奇倍体),其中三倍体成份占50—60％。如果仅仅由四倍体(母)或二倍体(父)株上收获种子,能否提高其三倍体百分率,发挥更大经济效益,本试验证明,母本株上收获的种子,其三倍体率略有提高,根产量也有增加趋势,但不显著,含糖率无变化。因此,没有必要将目前这种采种方式改为从母本或父本上单收种子,因为它在经济上不合算,不能增加经济效益。 相似文献
2.
通过观察８２株大麦花药培养再生植株根实细胞有丝分裂和５６株花粉母细胞（ＰＭＣ）减数分裂过程中染色体的结构和分离情况，结果表明，单倍体和二倍体植株各为１７．１％和３５．４％，混倍体植株４７．５％，在混倍体植株中，有二倍体，三倍体，四倍体甚至六倍体细胞和一些非整倍体细胞，但仍以单倍体，二倍体和四倍体细胞为主，根尖细胞有线分裂过程中有染色体结构的变异，如染色体断片，环状染色体等，二倍体ＰＭＣ减数分裂过程 相似文献
3.
通过观察82株大麦花药培养再生植株根尖细胞有丝分裂和56株花粉母细胞（PMC）减数分裂过程中染色体的结构和分离情况。结果表明，单倍体和二倍体植株各为17．1％和35．4％，混倍体植株47．5％，在混倍体植株中，有二倍体、三倍体、四倍体甚至六倍体细胞和一些非整倍体细胞，但仍以单倍体、二倍体和四倍体细胞为主。根尖细胞有丝分裂过程中有染色体结构的变异，如染色体断片，环状染色体等。二倍体PMC减数分裂过程中染色体分离有异常现象，如染色体“桥”，但绝大多数能正常完成。而单倍体和四倍体不能正常完成，单倍体染色体分离以2：5或3：4为主，并在中后期Ⅰ看到染色单体分离现象，四倍体细胞染色体有多种联会形式。酯酶同工酶（EST）聚丙烯酰胺凝胶电泳（PAGE）结果表明，利用Estl座位不同等位基因的分离规律可检出再生植株中的纯合体与非纯合体。不同的二倍体花粉植株在性状上出现明显的分离现象，观察到二类性状有显著差异的植株，Ⅰ类和Ⅱ类，Ⅰ类占6．6％，Ⅱ类占93．4。 相似文献
4.
5.
同源四倍体水稻与非洲栽培稻杂交的效果 总被引：2，自引：3，他引：2
以4份同源四倍体水稻(Oryza sativa,2n=4x=48)和4份二倍体水稻(Oryza sativa,2n=2x=24)为母本,以4份非洲栽培稻(Oryza glaberrima,2n=2x=24)为父本进行远缘杂交配组,共配制32个杂交组合。研究结果表明,非洲栽培稻分别与亚洲栽培稻中的两种倍性水平的水稻品系进行杂交均表现出一定的可交配性,生殖隔离并不很严格。然而,不同倍性的亚洲栽培稻与非洲栽培稻杂交,其结实率表现出明显的差异。二倍体水稻与非洲栽培稻不容易杂交,其结实率比较低(0．32％—1．93％),而同源四倍体水稻与非洲栽培稻较容易杂交,其结实率比较高(1．22％—8．86％,)。由此认为,利用同源四倍体水稻为母本与非洲栽培稻杂交更容易将后者的遗传物质引入亚洲栽培稻。 相似文献
6.
7.
同源四倍体水稻与非洲栽培稻杂交的后效性研究 总被引：2，自引：0，他引：2
利用亚洲栽培稻中的4份同源四倍体水稻(O.sativa,2n=4x=48)和相应的4份二倍体水稻(O.sativa,2n=2x=24)为母本,以4份非洲栽培稻(O.glaberrima,2n=2x=24)为花粉供体进行远缘杂交后,对其杂种后代的分离动态进行了研究.结果表明,不同倍性的普通栽培稻与非洲栽培稻之间杂交后代的结实率以二倍体普通栽培稻的较高.在配制的32个杂交组合中,其杂种第1代群体均表现出明显的营养生长优势.从群体的生长势来看,杂种第2代群体比杂种第1代群体要弱一些;在杂种第2代群体中,以同源四倍体水稻为母本的杂交组合的分离现象比以二倍体水稻为母本的杂交组合的分离现象更明显.在各杂交组合的第3代群体中,从植株的株叶形态和生育期来看,株系间的差异和株系内的变异依然很明显,变异频率更宽,变异种类更多.在普通栽培稻与非洲栽培稻的杂交组合中,育性变异、生长势变异、株叶形态变异、染色体变异和结实性变异等是较易发现的变异现象. 相似文献
8.
同源四倍体水稻与狼尾草杂交的效果 总被引：17，自引：0，他引：17
利用A P IV (4)、IR36(4)、紫血稻(4)、测64(4)、明恢63(4)、IR28(4)、测90(4) 和桂99(4) 等8 个同源四倍体水稻(Oryza sativa, 2n= 4x= 48) 为杂交母本, 以狼尾草(P ennisetum alopecuroides, 2n= 2x= 18) 为杂交父本进行杂交, 获得了实粒种子。但是, 在以A P IV (2)、测90(2) 和紫血稻(2) 这3 个二倍体水稻(Oryza sativa, 2n= 2x= 24) 为杂交母本, 以狼尾草为杂交父本的杂交组合中却没有获得实粒种子。在授粉后狼尾草的花粉粒能诱导杂交母本的子房发生明显膨大。在同源四倍体水稻中的子房膨大效应比二倍体水稻中的子房膨大效应更加明显。在以同源四倍体水稻为杂交母本的杂交组合中, 可以获得一些实粒种子, 但是, 如果在授粉前利用DH 溶液对同源四倍体水稻的去雄颖花进行处理后再授狼尾草的花粉粒则能获得更多的实粒种子。结果暗示由于同源四倍体水稻具有比较弱的有性生殖能力, 在远缘杂交中它们是比较好的杂交母本。 相似文献
9.
利用体细胞杂交获取马铃薯软腐病的抗性 总被引：1，自引：0，他引：1
对马铃薯四倍体栽培种和二倍体野生种Solanumbrevidens的体细胞杂种通过叶片离体培养获得的四倍体植株,以及用四倍体栽培种进行回交获得的五倍体植株的块茎对软腐病的抗性进行了测定。结果表明,由体细胞杂种通过叶片组织离体培养再生植株中,有一个株系SC107对软腐病菌Erwiniacarotovora具有较强的抗性。在用不抗软腐病的马铃薯栽培种对体细胞杂种进行回交获得的杂种后代中,大部分株系对软腐病菌具有高水平的抗性,从而说明Solanumbrevidens对软腐病的抗性基因已转移到马铃薯栽培种。 相似文献
10.
火龙果为仙人掌科量天尺属和蛇鞭柱属植物,不同类型火龙果种质的染色体倍性尚不明确。为明确所收集的种质资源以及创制的新材料的染色体倍性,利用流式细胞技术对29份火龙果材料进行了倍性鉴定。结果显示,供试的18份种质资源中共鉴定出二倍体火龙果14份,四倍体4份,无三倍体材料。通过不同倍性亲本杂交和秋水仙素诱变所创制的8份后代材料经鉴定发现有二倍体材料1份,三倍体材料3份,四倍体材料4份,这表明火龙果属间杂交和化学诱变可获得多倍体材料。研究结果对火龙果资源的遗传学评价以及开展倍性杂交育种提供重要的参考依据。 相似文献
11.
A. Barekye P. TongoonaJ. Derera M.D. LaingW.K. Tushemereirwe 《Field Crops Research》2011,122(3):284-289
The generation of banana triploids from tetraploid-diploid crosses requires knowledge on the influence of the parents on black Sigatoka resistance and agronomic traits to the triploid progenies. The objective of this investigation was to determine the influence of tetraploid and diploid parents on black Sigatoka resistance and agronomic traits in the triploid progenies generated from tetraploid-diploid crosses. The mating scheme was designed as a 4 × 5 North Carolina II mating design. Due to problems in seed set and germination, progenies from 2 male parents with 4 female parents were evaluated at two sites in Uganda. The results showed that the male-parent triploid progeny heritability estimate for the number of leaves at harvest was greater than the female parent estimate. The diploid parents had higher correlation coefficients for the total leaves at harvest with the triploid progenies than tetraploid parents with triploid progenies. Disease development over time took more days in diploid parents than in the tetraploid parents with the triploid progenies as intermediates. These results suggested that diploids transferred black Sigatoka resistance to the triploid progenies as measured by the number of standing leaves and disease development overtime. There was a positive correlation (P < 0.05) between tetraploid female parents and triploid progenies for plant height and bunch weight. The triploid progeny-tetraploid female parent heritability estimates for plant height (0.92) and bunch weight (0.72) were highly significant. These results indicated that the female synthetic tetraploids influenced plant height and bunch weight in the triploid progenies. Therefore, it is important to select the tetraploids with heavy bunches to effectively improve yield in triploid progenies generated by tetraploid-diploid crosses. The tetraploid-diploid progenies had a significant (P < 0.05) family-by-site interaction for bunch weight indicating that new banana genotypes need to be tested across different environments to select stable genotypes to promote to end-users. 相似文献
12.
13.
橡胶树不同倍性的气孔性状差异研究 总被引：2，自引：0，他引：2
以通过流式细胞倍性检测鉴定出的橡胶树二倍体、三倍体、四倍体植株为研究对象,对不同倍性植株的气孔性状进行观察和统计。结果表明:不同倍性间的橡胶树叶片的气孔长度、气孔宽度、气孔密度均存在极显著差异。随着橡胶树倍性的提高,气孔的长度和宽度均增大,而气孔密度减小。二倍体、三倍体和四倍体的气孔长度范围分别为10.65~15.29、14.04~18.89、15.15~19.37μm,气孔宽度范围分别为7.13~10.65、8.58~11.83、10.38~13.83μm,气孔密度范围分别为520.62~867.69、402.53~764.80、381.79~555.32个/mm~2。以气孔长度15.15μm、气孔宽度10.38μm和气孔密度555.32个/mm~2为临界值,可以鉴定二、四倍体混合群体中的四倍体。三倍体和二倍体、四倍体在气孔长度值、宽度值和密度值在分布区间上均存在较大的重复,但以气孔长度14.04μm,气孔宽度8.58μm和气孔密度764.80个/mm~2为临界值,可以筛除二、三、四倍体混合群体中的部分二倍体,提高多倍体鉴定的效率。 相似文献
14.
Oryzalin Treatment of Potato Diploids Yields Tetraploid and Chimeric Plants from which Euploids could be Derived by Callus Induction 总被引：2，自引：0，他引：2
Shoot apices from six diploid potato genotypes for polyploidisation were treated with oryzalin and colchicine solutions at
different concentrations and incubation times. In addition to chimeric plants, diploids, one octoploid and completely ploidy
doubled plants (4x) were regenerated in these experiments. Tetraploid plants were obtained for three of the six genotypes treated with oryzalin,
and no tetraploid plants were obtained after colchicine treatments of any of the genotypes. The best result of 43% tetraploid
plants was achieved using 28.8 μM oryzalin and 24 h of incubation with the L37 genotype. Moreover, we determined that doubled
plants should not be selected on the basis of a single measurement and require additional ploidy checks in successive clonal
generations. Some L37 plants that were initially identified as tetraploids by flow cytometry produced diploid or mixoploid
plants in the next clonal generation. Morphological characters of doubled L37 plants were compared with the original genotype.
The PVY resistance present in a parental clone was maintained in all regenerants and significant differences among ploidy
variants were found for some quantitative characters. Molecular AFLP analyses did not show any differences among genotypes.
Since polyploidizing substances may produce a large proportion of chimeric plants, we applied a method to increase the number
of tetraploid plants. Callus culture of chimeric leaf explants was performed on regeneration medium and tetraploid shoots
were obtained in four of the six genotypes tested. The best result of 40% tetraploid plants was achieved with explants from
the L37 genotype. This method was successful in producing additional tetraploid genotypes from mixoploid plants obtained after
oryzalin treatments. 相似文献
15.
Solanum tuberosum Group Tuberosum haploids (2n = 2x = 24) were inter-mated using bulk pollen. Nearly half of the resulting progeny were tetraploid, arising from bilateral sexual polyploidization. Subsequent yield trials indicated that the diploid progeny did not yield significantly more than the original haploids, but the tetraploid progeny did yield significantly more than their diploid sibs and the original haploids. Tetraploid cultivars and conventional tetraploid breeding families significantly out-yielded the haploid-derived tetraploids. These results and the theoretical considerations which are presented indicate that inter-mating haploidsper se does not increase heterozygosity. More importantly, these results indicate that without the introduction of new germplasm, haploidization followed by repolyploidization can only be expected to result in tetraploids with heterozygosity equal to or below that of their parents. 相似文献
16.
Two thousand and fifty-five pollinations were made between the cultivar Russet Burbank and Group Phureja pollinator clone 1.22, resulting in 882 fruit and 253 seeds. One-hundred and fifty progeny grew from these seeds, of which 6 were haploids, 143 were triploids and 1 was tetraploid. None of the haploids flowered. The predominance of triploids was unusual for Gp. Tuberosum cultivars, but it does not indicate a breakdown of the “triploid block” because of the low seed set. These results are similar to those found during haploid extraction from Gp. Andigena, suggesting the possibility that Gp. Andigena may have been involved in the parentage of Russet Burbank. 相似文献
17.
Four plants of each of 15 derived tetraploids from a cross of B0749-2F (2n=4×=48) and DM91-5 (2n=2×=24) were planted in the greenhouse at Beltsville, Maryland, in January 1992. The female tetraploid parent is a late blight resistant selection from theTuberosum germplasm base. The male diploid parent is a high dry matter selection from the GroupPhureja-Stenotomum germplasm base. For each derived tetraploid, the percent normal, abnormal, and total pollen germinationin vitro were determined on 2–4 flowers per derived tetraploid harvested 3–4 times during a three-week period in April. The percent normal, abnormal, and total pollen germination ranged from 0.6 to 27.5, 0.1 to 7.6, and 1.4 to 36.6, respectively. Pollen tube growth, measured 2 hours from initiation of germination, ranged from 22 to 130 nm. Four general types of abnormalities in the pollen were identified: a) stunted and curly pollen tubes; b) damaged membranes allowing leakage of cytoplasmic contents; c) pollen grains with two or more pollen tubes; and d) split pollen tubes. In hybridizations with Atlantic as the female parent, 11 out of 15 of these derived tetraploids produced viable seeds. All 15 derived tetraploids were female fertile. These results suggest that utilizing derived tetraploids from theTuberosum andPhureja-Stenotomum germplasm bases in future breeding efforts should not present any great difficulty. However, hybridizations involving these derived tetraploids were more successful when the derived tetraploids were the female parent. 相似文献
18.
花生野生资源品质分析及杂交试验 总被引：2，自引：0，他引：2
对供试３４份花生野生资源进行了抗病性鉴定，其中部份参试材料作了品质分析及杂交试验．结果表明，花生野生种对三大叶部病害抗性较强；高蛋白质材料较多，也有高油份材料；花生区组二倍体野生种正反交其花果率差异较大，杂种Ｆ１经染色体加倍后，地上部超亲杂种优势明显，正反交后代花粉粒可育率相差悬殊；花生不同区组远缘杂交授粉后施用激素的花针率比不施激素的高，施用赤霉素比激动素效果好；适宜的赤霉素施用浓度为８７．５ｐｐｍ。 相似文献
19.
Diploid (2n = 2× = 24) potato (Solarium) species that produce 2n gametes are being utilized in potato breeding programs. Three breeding schemes involving these diploids are presently used by potato breeders to transfer this genetic material from diploid parents to their tetraploid offspring. Derived tetraploids may arise through tetraploid × diploid, tetraploid × haploid-species, or diploid × diploid hybridizations. The inbreeding coefficient of derived tetraploids is a complex function of the coancestry of the parents, the inbreeding of the parents, the coefficient of double reduction in the tetraploid parent, and the frequency of single exchange tetrads in the diploid parent(s), and it depends on the mechanism of 2n gamete formation. For the two breeding strategies involving tetraploid female parents, there is less inbreeding in the derived tetraploid from a diploid parent producing 2n pollen by first division restitution than 2n pollen by second division restitution when the frequency of single exchange tetrads in the diploid is less than 2/3. In bilateral sexual polyploidization, the inbreeding coefficient of a derived tetraploid for a given set of parents from a first division × first division restitution cross is less than the inbreeding coefficient of a second division × first division restitution cross which is less than the inbreeding coefficient of a second division × second division cross when the frequency of single exchange tetrads is less than 2/3. 相似文献
20.
芝麻野生种与栽培种的交配能力 总被引：1，自引：0，他引：1
石淑稳 《中国油料作物学报》1993,(2)
本试验以野生种(S.schinianum)和栽培种(S.indicum L.)宜阳白、中芝5号、鄂芝1号和中芝7号为亲本进行了正反杂交。以栽培种作母本,一次授粉和重复授粉均不能产生种子。以S.schinzianum作母本则产生秕种子,重复授粉提高秕籽率,但这些秕种子于土中不能发芽。离体培养授粉后8天的幼蒴仅野生种作母本的组合产生了小植株、植株的形态特征与野生种相似。 相似文献