排序方式： 共有14条查询结果，搜索用时 15 毫秒
1.
Growth of triploid oyster, Crassostrea madrasensis (Preston) 总被引：1，自引：0，他引：1
The performance of I and II meiotic triploids and control oysters (Crassostrea madrasensis) reared at Tuticorin Bay was compared to determine if the improvements in the growth of edible oysters were additive to faster growth in triploids. After a grow‐out period of 12 months, both mean whole weights and shell heights were in order I meiotic triploid>II meiotic triploid>control. Mean whole weights and shell height of different oyster lines were all significantly different (P<0.05). On an average, larger morphological traits indicated that growth improvements from triploids were additive, and throughout the study triploid oysters maintained faster growth rate than their diploid siblings. Condition index and adductor muscle diameter of both triploids were higher than those of control. 相似文献
2.
Identification of triploid Citrus by isozyme analysis 总被引：3，自引：0，他引：3
Summary Seedlessness is a desirable horticultural attribute in Citrus and is positively associated with triploidy. The conventional cytological method for triploid identification is a laborious technique involving the preparation of root tips for chromosomal analysis. Digital densitometry of isozymes, however, offers the possibility of distinguishing triploid Citrus from large populations of seedlings both quickly and cheaply. Where there are no gene dosage regulation effects, greater band density should be evident in the allozyme contributed by the diploid gamete for a heterozygous locus. The isozymes of 4 enzymes; malate dehydrogenase, 6-phosphogluconate dehydrogenase, shikimate dehydrogenase, and phosphoglucose isomerase, were investigated with polyacrylamide gel electrophoresis. Band densities of these isozymes for triploid Citrus, their diploid siblings and diploid progenitors were measured using a digital densitometer. Of the 4 enzymes investigated only allozymes for shikimate dehydrogenase exhibited consistent differences over a wide range of Citrus cultivars. Greater band density was evident in the allozyme contributed by the diploid gamete. The band density ratio between allozymes for triploid Citrus was close to 0.5, while for diploid Citrus band density ratios were close to 1.0. This effect is due to the extra protein coded by the additional gene dose and was not observed in diploids. Shikimate dehydrogenase proved to be an accurate molecular marker for distinguishing between diploid and triploid Citrus for heterozygous progeny.Abbreviations PAGE
Polyacrylamide gel electrophoresis
- MDH
malate dehydrogenase
- 6PGD
6-phosphogluconate dehydrogenase
- SkDH
shikimate dehydrogenase
- PGI
phosphoglucose isomerase 相似文献
3.
Summary
Solanum commersonii Dun. is a diploid (2n=2x=24, 1EBN) wild species of potential value for potato breeding. It is a reproductively isolated species and cannot be crossed with Tuberosum haploids (2n=2x=24, 2EBN) or other diploid 2EBNSolanum species. In order to overcome the EBN barriers, triploid hybrids were produced between Phureja-Tuberosum haploid hybrids, which form 2n pollen grains by parallel spindles, and tetraploidS. commersonii. Microsporogenesis analysis of the triploids indicated a trend towards low values of chromosome distribution at Anaphase I; lagging chromosomes were often observed as well. Despite these abnormalities, the percentage of stainable pollen was very high, ranging from 5.0% to 74.3%. A high variation in pollen grain diameter was also evident. Parallel and tripolar orientation of spindles at Metaphase II of microsporogenesis was a common feature of all the triploids analyzed, but dyads and triads were observed at a very low frequency. Therefore, also the frequency of 2n pollen was very low; the different size of stainable pollen appears to represent the ploidy levels which are possible according to the distribution of chromosomes in Anaphase I. The results obtained also suggest thatS. commersonii could have minor genes acting at the end of meiosis in such a way that, despite the presence of parallel/tripolar spindles, dyads/triads are not formed.Contribution no. 124 from the Research Center for Vegetable Breeding. 相似文献
4.
5.
单胚性二倍体为母本与异源四倍体杂交大规模创制柑橘三倍体 总被引：1，自引：1，他引：0
【目的】以单胚性的二倍体柑橘品种为母本与异源四倍体体细胞杂种杂交培育三倍体植株。【方法】选择亲本配置杂交组合进行人工授粉,授粉后70—100 d采幼果进行胚挽救,以流式细胞仪结合根尖染色体压片对再生植株进行倍性检测,最后进行SSR分子标记鉴定。【结果】2009—2012连续4年,以8个二倍体为母本、以4个异源四倍体体细胞杂种为父本,共配置14个倍性杂交组合,授粉花数3 347朵,坐果数678个,平均坐果率20.26%。实施胚挽救的果实数505个,培养种子12 357粒,经生芽、生根诱导培养共获得1 022个株系。通过对再生植株的倍性检测,共获得三倍体植株755个株系,四倍体19个株系。对华农红柚 × NH组合的三倍体、四倍体后代进行分子鉴定,表明三倍体和四倍体全部为双亲的有性杂种后代。【结论】本研究通过杂交获得的三倍体为我国无籽柑橘品种选育奠定了材料基础;同时获得的四倍体后代也为未来的柑橘三倍体育种提供了优良的亲本材料。 相似文献
6.
微卫星标记在长牡蛎三倍体鉴定中的应用 总被引：1，自引：1，他引：0
为开发一种简单有效的倍性检测方法对长牡蛎三倍体诱导结果进行准确评估,本实验采用细胞松弛素B抑制第二极体释放诱导产生长牡蛎三倍体,选用7个微卫星位点扩增基因组DNA,通过亲子代基因分型进行倍性检测,检测结果采用流式细胞仪加以验证,以评估微卫星标记倍性检测的准确性。另外,本研究探讨了准确鉴定倍性所需的微卫星标记数量与微卫星—着丝粒重组率(y)之间的关系,以期为其他物种采用分子标记进行倍性检测提供理论依据。结果显示,细胞松弛素B诱导产生的115个长牡蛎子代经7个微卫星位点鉴定得到40个三倍体,与流式细胞仪检测结果一致,准确率达到100%,7个微卫星位点的(1-y)的乘积为0.005。随机挑选6个位点,也可鉴定出所有三倍体,(1-y)的乘积为0.005~0.042。研究表明,本研究中开发的微卫星标记可以简单高效地鉴定长牡蛎三倍体,微卫星位点的(1-y)的乘积小于0.005,倍性检测的准确率可达100%,采用微卫星标记进行倍性检测对于加速长牡蛎三倍体育种进程具有十分重要的意义。 相似文献
7.
极端温度处理白杨雌花培育三倍体植株的研究 总被引：7，自引：1，他引：6
采用极端温度的物理方法处理毛新杨、银腺杨、银毛杨雌花芽，均可获得三倍体。结果表明：①雌花枝水倍１－５ｄ期间是处理雌花芽的有效时期；②高温处理化芽检测出１０株三倍体，处理温以４０，４４℃有效，分别获得８株、２株三倍体，其中４０℃高温处理效果最佳；③低温处理雌花芽检测出３株三倍体，４，－２℃低温处理均有效果，分别获得１株、２株三倍体，－２℃处理效果较好；④处理时间分别为：４０℃高温处理水倍１－５ｄ的花 相似文献
8.
以卵裂率、D形幼虫发生率、三倍体率等为指标,比较了高盐、低温及咖啡因诱导香港牡蛎(Crassostrea hongkongensis)三倍体幼虫的效果,同时也分析了诱导因子强度(或浓度)、持续时间、受精卵密度及受精后开始处理时间对诱导效果的影响。结果表明,高盐诱导三倍体的最适条件组合是在卵子密度1.0×107个/L的情况下受精后15 min,用盐度40的海水持续处理10 min,此时卵裂率为(39.60±2.14)%, D形幼虫发生率为(31.46±1.06)%,三倍体率可以达到(59.53±5.90)%;低温诱导三倍体的最适条件组合是密度为2.0×10~7个/L的卵子在受精后15 min,用10℃海水持续处理10 min,此时卵裂率为(21.00±4.90)%, D形幼虫发生率为(12.68±1.21)%,三倍体率为(51.09±2.67)%;咖啡因诱导三倍体的最适条件组合是卵子密度为1.0×10~8个/L,用咖啡因终浓度2.0g/L的海水在受精后15min,持续处理20 min,卵裂率为(85.46±4.78)%, D形幼虫发生率为(71.79±3.92)%,三倍体率可以达到(56.36±2.07)%。最适诱导条件下,咖啡因的诱导效率指数0.405高于高盐处理0.187、低温处理0.065。高盐及低温处理方法诱导出的幼虫三倍体率随生长降低极快且存活率低于咖啡因诱导方法,说明3种方法中咖啡因可能更适合用于香港牡蛎三倍体幼虫的诱导。本研究为香港牡蛎三倍体育种提供了基础数据和实践经验。 相似文献
9.
Summary Reciprocal crosses were made between highbush Vaccinium corymbosum L. cultivars (4X) and high, medium and low frequency diplandroid pollen producing diploid clones of V. elliotti (Chapm.) and diploid pubescent forms of V. corymbosum. Pollination of 3,342 flowers produced 15 hybrids-11 tetraploids and 4 triploids. All V. elliottii hybrids were tetraploid while each successful diploid-tetraploid V. corymbosum cross produced at least one triploid. The ratio of tetraploid hybrids to 100 pollinations (H: 100P) was considered to be the best criterion for assessing crossability. Vaccinium elliottii produced a total of 8 4X hybrids while 2X V. corymbosum only produced 3. Vaccinium elliottii was more successful as a female parent and diploid V. corymbosum only produced hybrids as male parents. High frequency diplandroid clones showed a lower mean crossability as pollen parents (H: 100P=0.2) than medium frequency diplandroid clones (H: 100P=0.8). As predicted, 0% diplandroid clones wer unsuccessful as pollen parents. Unreduced pollen production was essential for tetraploid hybrid production in 4X×2X crosses. There appeared to be no consistent, inherent pattern between 2n pollen and 2n egg production in a clone nor was a tetraploid genotype effect on crossability consistently observed.Paper No. 10781 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, NC., 27695-7601 相似文献
10.