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鲁西牛的染色体研究 总被引:1,自引:0,他引:1
研究了40头鲁西牛(♂37,♀3,2n=60)染色体的 G 带,R 带,C 带及Ag-NOR,着重分析了 y 染色体的形态及带型。在常规 Giemsa 染色的分裂相上,y染色体和小的常染色体形态相近。经常规—C 带连续染色,准确识别出 y 染色体之后测量了18条 y 染色体,臂比为3.19,属亚端着丝点染色体。y 染色体的着丝点区和短臂与常染色体的着丝点区和短臂在 G 带、C 带的带型上差别很大,表明构成它们 DNA的硷基成份有差别。统计的152个细胞的 Ag-NOR 中,平均每细胞 Ag-NOR 数为5.81±1.38,变化范围2—9。按染色体长度排列,NOR 位于2、3、4、11、22(或21)和28号常染色体末端。第22(或21)号染色体上存在 NOR 在其它牛种上尚未有过报道。 相似文献
45.
The meiotic behavior of three tall fescue (Festuca arundinacea, 2n = 6x = 42) genotypes, giant fescue (F. gigantea, 2n = 6x = 42), and their reciprocal F1 hybrids and C1, amphiploids was evaluated to determine the parental genomic relationships. Isozyme banding patterns were used to confirm the parental identity of the hybrids and amphiploids. At meta-phase I, the parents had predominantly bivalent pairing. The hybrids had an average of 9.51 I, 16.02 II, 0.12 III, 0.02 IV, and the amphiploids had 2.17 I, 38.82 II, 0.60 III, 0.58 IV, 0.01 V—VIII. The prevalence of bivalent pairing in both hybrids and amphiploids suggested a homoeologous relationship between the six genomes, with four of the six being more closely related. Bivalent pairing in the amphiploids indicated genetic regulation of chromosome pairing. Zymograms were obtained for acid phosphatase (ACPH), alcohol dehydrogenase (ADH), glutamate oxaloacetate transaminase (GOT), malate dehydrogenase (MDH), 6-phosphogluconate dehydrogenase (6-PGD) and phosphoglucoisomerase (PGI). The three tall fescue and giant fescue parents had different zymograms for ACPH, MDH, 6-PGD and PGI; thus, the tall fescue parents of the hybrids and amphiploids could be determined based on the banding patterns of these four enzymes. Phenotypes were determined for ACPH-1, PGI-2 and 6-PGD-1. ACPH-1 may be used to follow the introgression of giant fescue chromatin into a certain tall fescue genotype. 相似文献
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Summary A study was undertaken to evaluate the breeding behaviour and to identify a spontaneously produced putative chromosomal deletion in the winter wheat (Triticum aestivum L. em. Thell.) cv Norstar. Male and female transmission studies of plants heterozygous for the deletion chromosome indicated 9.5% and 48.8% transmission through the pollen and the egg, respectively. Meiotic analyses of progeny from deletion heterozygotes indicated that the deletion chromosome was eliminated from half of the plants, which agreed with the male and female transmission frequencies. Testcrosses of the deletion chromosome with telocentrics and nullisomic-tetrasomic combinations suggested that the deletion involved the long arm of chromosome 5D. This was confirmed by restriction fragment length polymorphism (RFLP) analysis. Also, monosomic plants obtained in progeny of deletion heterozygotes were shown to be monosomic for 5D. Studies of plants homozygous for the deletion showed relatively normal pairing between the deletion chromosomes, and with the short arm (5DS), but not the long arm (5DL). Deletion homozygotes were self-sterile, and morphologically similar to plants nullisomic for 5D, but plants that also contained 5DL, or a homoeologous chromosome were self-fertile and had normal morphology. Studies of chromosome morphology indicated that the deletion chromosome was metacentric, and the length of the long arm was reduced by approximately 60%. RFLP studies showed that, in terms of genetic distance, 90% of the arm was missing. 相似文献
47.
End-use quality of wheat for noodles is influenced by polyphenol oxidase activity and its corresponding substrates. This study investigated the chromosomal location of genes that determine phenol colour reaction of kernels in tetraploid wheat using aneuploid stocks. Polyphenol oxidase activity was estimated by the colour reaction of kernels to phenol solution. It was found that the genes located on homoeologous group 2 chromosomes have an important effect on the level of phenol colour reaction of kernels. The genes (Tc1 and Tc2) responsible for high phenol colour reaction of kernels were mapped to the long arms of chromosome 2A and chromosome 2B, respectively. The map distances were estimated to be 46.8 cM for Tc1 and 40.7 cM for Tc2 from the centromere using double-diltelosomics of durum wheat. 相似文献
48.
Breeding of Raphanus sativus‐Brassica rapa monosomic chromosome addition lines (MALs, 2n = 19) was carried out by backcrossing the synthesized amphidiploid line, Raphanobrassica (R. sativus×B. rapa, 2n = 38, RRAA, line RA89) with R. sativus cv. ‘Shogoin’ (2n = 18, RR). In the first cross of Raphanobrassica× radish, four sesquidiploidal BC1 plants (2n = 28, RRA, RA89‐36‐1, RA89‐31‐1, RA89‐31‐2, RA89‐31‐3) were successfully developed. In these plants, the chromosome configurations of 9II + 10I and 10II + 8I were observed frequently at first metaphase (MI) of meiosis in pollen mother cells (PMCs). The RA 89‐36‐1 plant produced many seeds in the reciprocal backcrosses with radish. About 50% of the BC2 plants obtained from the cross of RA89‐36‐1 plant × radish were 2n = 19 plants, followed by 2n = 18 plants (24%) and 2n = 20 plants (19%). In the reciprocal cross, 2n = 19 plants were also developed at the rate of 40%. From analysis of specific morphological traits, 2n = 19 plants were classified into eight types (a‐h). When 25 selected primers were used in polyacrylamide gel electrophoresis, random amplified polymorphic DNA (RAPD) markers derived from B. rapa for each type of MAL were detected in numbers between three for e‐type and 16 for b‐type. RAPD markers specific for each type alone were from one (OPE 05‐344) for h‐type to nine for b‐type. In the g‐type, no marker specific to this type alone was observed. However, 19 bands were common between at least two types. These MAL plants exhibited predominantly the chromosome configuration of 9II + 1I at MI of PMCs, pollen and seed fertility being the same level as the radish cv. ‘Shogoin’. From the morphological traits and DNA markers, eight different MAL types among 10 expected were identified. 相似文献
49.
Shimelis?HusseinEmail author Johan?J.?Spies Zakkie?A.?Pretorius Maryke?T.?Labuschagne 《Euphytica》2005,141(3):209-216
Langdon durum D-genome disomic substitution lines were used to study the chromosome locations of adult-plant leaf rust resistance genes identified from tetraploid wheat accessions. The accessions are 104 (Triticum turgidum subsp. dicoccum var. arras) and 127 (T. turgidum subsp. durum var. aestivum). The complete sets of the substitution lines were crossed as female parents with the accessions and F1 double monosomic individuals selected at metaphase I. Segregating F2 individuals were inoculated during the flag leaf stage with pathotype UVPrt2 of Puccinia triticina. The substitution analysis involving accession 104 showed that the gene for leaf rust resistance is located on chromosome 6B. The analysis with accession 127 indicated that chromosome 4A carries a gene for leaf rust resistance. The two novel genes are temporarily designated as Lrac104 and Lrac127, respectively from accessions 104 and 127. 相似文献
50.
Rod or ring bivalents at metaphase I (MI) reflect whether crossing-over has occurred on one or both pairs of chromosome arms, respectively, during meiotic prophase (pachytene). In cultivated barley ( Hordeum vulgare ) the highest frequencies of rod bivalents were found for satellite chromosomes (either 5H or 6H). To distinguish between chromosome 5H and 6H associations, a recombinant line derived from an H. vulgare × H. bulbosum hybrid with a hemizygous introgression from H. bulbosum on the short arm of chromosome 6H was probed with 45S rDNA and pSc119.2 using fluorescent in situ hybridization and compared with non-recombinant H. vulgare. The frequencies of rod bivalents, caused by failure of the short arms of 5H chromosomes (5HS) to associate during meiosis in the recombinant line, were similar to the frequencies of rod bivalents involving the satellite chromosomes in H. vulgare. Hence, rod bivalent formation in H. vulgare satellite chromosomes is probably based on reduced association of 5HS, corresponding to a low frequency of genetic recombination. 5HS is, therefore, more likely to show linkage disequilibrium than the other chromosome arms. 相似文献