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61.
稻属间杂种花粉植株的细胞遗传学研究 总被引:1,自引:0,他引:1
以栽培稻02428与紧穗野生稻间不育F1杂种(2n=24,AC)为材料进行花约培养,共接种花约32688个,获得再生绿苗13株及白化苗两株,愈伤诱导率与分化率分别为0.14%和34.78%。有9朱花粉绿苗长至成熟,均表现长芒、紫柱头、强感光及易落粒等野生亲本的特性。细胞学结果进一步表明,其中4株为二倍体(2n=24),形态上琚的F1杂种相似,花粉母细胞中期Ⅰ亦只能见到少数二价体;另5株则为四倍体( 相似文献
62.
Summary Male meiosis of the interspecific hybrid between Allium roylei and A. cepa is undisturbed relative to its parents. Based on meiotic data, A. roylei is concluded to be a closer relative of A. cepa than A. fistulosum. Segregation ratios for downy mildew resistance among BC1 and F2 progenies from the F1 between A. roylei and A. cepa indicate the presence of two dominantly inherited, weakly linked nuclear resistance genes, Pd
1 and Pd
2, in A. roylei (recombination frequency 0.32±0.03). Presumably Pd
1 and Pd
2are the first genes described in Allium residing in one linkage group. The prospects of exploiting A. roylei in onion breeding seem very promising. 相似文献
63.
用对甘薯组 A 群的种 I.tiliacea 和 I.gracilis 与 B 群的种 I.trifida 和 I.littoralis 杂交观察授粉后的胚胎发生的情况,发现授粉后7小时,花粉粒均能在柱头上发芽,花粉管也能通过花柱到达胚珠。在授粉后两天的子房内,可看到已受精、正受精、未受精等受精过程的各个阶段。此时以 B 群 K_(233-1)为母本的卵细胞受精率可达80% 相似文献
64.
Species relationships in the subgenus Ceratotropis (genus Vigna) as revealed by RAPD analysis 总被引:4,自引:0,他引:4
Akito Kaga Norihiko Tomooka Yoshinobu Egawa Kazuyoshi Hosaka Osamu Kamijima 《Euphytica》1996,88(1):17-24
Summary The genetic variation among 23 accessions of 5 species in the subgenus Ceratotropis, genus Vigna, were investigated by random amplified polymorphic DNA (RAPD) analysis. A total of 404 fragments amplified with 24 primers were scored and analyzed by cluster analysis. The accessions used were separated into two main groups with an average of 70% differences. Within the main groups, five subgroups were recognized, which are in complete agreement with taxonomic species. Wild forms were always grouped with their most closely related cultivated forms and they showed variation in each species. The largest intraspecific variation was found in V. radiata (mungbean), in which wild forms (V. radiata var. sublobata) were highly different from each other and from cultivated forms. V. angularis (adzuki bean) showed the least variation and thus, was probably differentiated in relatively recent times. 相似文献
65.
In this study, we report the use of ISSR to assess genetic diversity and to determine the relationships among ten cultivars
of common bean developed in Argentina and three materials from France. ISSR markers resolved two major groups corresponding
to the Andean and Mesoamerican gene pools of common bean. We compared the results of previous analysis, performed with RAPD
markers (Galván et al., 2001), with the results generated by means of ISSR. It appears that ISSR are better tools than RAPDs
to identify beans by gene pool of origin though they did not revealed as many differences between individuals as RAPDs.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
66.
Summary The production, vigour, and fertility of F1 hybrids between nine African species of the genus Cucumis L. were studied as a measure of the relationships between the species. Hybrid plants were obtained from 29 out of the 72 possible cross combinations. Two F1 hybrids died as seedlings, and 27 hybrids were raised to maturity. Pollen production and stainability varied greatly amongst these hybrids, as did fruit and seed set following self pollination and backcrossing with either parental species. The fruit shape of the hybrids was always intermediate between that of both parental species.Two species appeared to be closely related: C. prophetarum L. and C. anguria var. longipes
A. Meeuse. Most other species produced highly to moderately fertile F1 hybrids with at least one other species. C. metuliferus
Naud. produced only sterile hybrids with C. zeyheri
Sond. 2x. The results sustain the recent taxonomic classification of the genus (Jeffrey, 1980). 相似文献
67.
Kevin G. Smith 《Biological conservation》2005,123(4):433-441
The impacts of nonindigenous species on native ecosystems can be severe, sometimes leading to the extinction of native taxa. Interspecific competition is a potential mechanism of negative impact of invasive species, but few studies have conclusively demonstrated competition between native and nonindigenous taxa. In this study I used experimental manipulations to examine the competitive effects of the larvae of two widely introduced anurans, the cane toad, Bufo marinus, and the Cuban treefrog, Osteopilus septentrionalis, on the growth and development of the larvae of two native anurans (the southern toad, Bufo terrestris, and the green treefrog, Hyla cinerea). The presence of O. septentrionalis larvae consistently impacted growth and development of native larvae, resulting in reduced growth rates and delayed metamorphosis of both native species and smaller mass at metamorphosis of B. terrestris. Hyla cinerea larvae transformed at greater body masses when reared with the rapidly transforming nonindigenous species as a result of competitive release. The negative effects of O. septentrionalis on native larvae were generally significant whether native tadpoles were exposed to O. septentrionalis alone or in combination with B. marinus. In contrast, B. marinus tadpoles did not significantly impact the growth or development of either native species. Neither nonindigenous species significantly decreased the survivorship of native larvae, although a trend toward decreased survivorship was evident for H. cinerea. These results suggest that nonindigenous larval anurans may adversely impact native tadpole communities as a result of interspecific competition. 相似文献
68.
Yoko L. Dupont Dennis M. Hansen Alfredo Valido Jens M. Olesen 《Biological conservation》2004,118(3):301-311
The aim of this study was to investigate effects of introduced honey bees (Apis mellifera) on native pollination interactions of Echium wildpretii ssp. wildpretii in the sub-alpine desert of Tenerife. We selected two study populations, one dominated by honey bees, while the other was visited by many native insects. During peak activity period of insects, nectar was nearly completely depleted in flowers of the first, but not the latter population. Thus, a high abundance of honey bees may have suppressed visitation by native animals due to exploitative competition. Honey bees stayed longer and visited more flowers on the same inflorescence than native bees, thus potentially promoting self-pollination of the plants. Level of seed set and viability was similar in the two study populations. However, we cannot rule out long-term changes in genetic population structure due to changes in gene-flow patterns caused by foraging behaviour of honey bees vs. native flower-visitors. 相似文献
69.
Numerous studies have examined the role of light fraction (LF) organic matter in soil C and N cycling, but there is no published information on the amounts and nature of S in LF. The objective of this work was to characterize the S composition of LF in soils receiving different inputs of fertilizer S. Soils (0-7.5 cm) were taken from a long-term experiment (1952-1999) set up to examine the effects of single superphosphate (SP) (applied at 0, 188, or 376 kg ha−1 yr−1, which equates to 0, 21, and 42 kg SO4-S ha−1 yr−1) on the productivity of an irrigated, grass-clover pasture grazed by sheep. The S content of LF (separated by flotation on NaI solution with specific gravity 1.7) increased by ∼20-30% in response to SP. The LF was enriched in organic S compared with whole soil (S concentration in LF was ∼1000-1400 mg kg−1 vs ∼400-500 mg kg−1 in whole soil), but LF-S represented only 1.3-4.7% of soil S. Most (∼88%) of the S in LF was C-bonded, reflecting the dominance of this form of S in organic matter returned to the soil in dung and plant residues. Hydriodic acid (HI) reducible-S accounted for only ∼12% of LF-S, compared with 28-35% of whole soil organic S. Superphosphate tended to increase total soil N, due to improved clover growth. There was a strong positive relationship between total N and C-bonded S in whole soil and LF, whereas soil HI-S and N were not associated. Increases in C-bonded S where SP was applied appeared to be driven mainly by increases in soil N, which in turn were due to improved clover growth in response to phosphate supplied by SP. Increases in HI-S due to SP application were probably a direct response to inputs of S. As LF is a small pool of S, with a relatively wide C:S ratio (∼200:1), we concluded that it is unlikely to contribute a significant amount of plant-available S. 相似文献
70.
The wild species, Capsicum buforum Hunz. and C. lanceolatum(Greenm. ex J.D. Sm.) Morton and Standl. were hybridized to nine different Capsicum species to understand their taxonomic and genetic relationships. With C. buforum as the male parent, the compatibility to the nine species varied from species to species and ranged from producing under-developed embryo, seed coat, seedless fruit, to no fruit set. When C. buforum was the female parent, it was incompatible (no fruit set) to the nine Capsicum species tested. When C. lanceolatum was the female parent, the hybridizations to the other species ranged from aborted embryo, seed coat, seedless fruit or no fruit. As a pollen parent, C. lanceolatum was incompatible (no fruit set) to the species investigated. In pollen mother cells (PMCs) of C. buforum, 24 chromosomes (n = 12) paired as 12 bivalents with chromosome lagging at meiotic anaphase-I. Twenty-six chromosomes (n = 13) were detected in PMCs of C. lanceolatum. In C. lanceolatum most chromosomes paired as bivalents, but one quadrivalent was observed in some cells. C. buforum was found to be self-incompatible, while C. lanceolatum was self-compatible. 相似文献