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81.
Summary An investigation was undertaken on the storage characteristics of pollen collected from two English rose cultivars. A rapid decline in viability was observed in pollen stored at +4° C and –20° C, whereas the viability of pollen, stored at ultra-low temperature (–196° C), remained constant. Cryopreserved pollen was shown to retain its ability for fertilisation. The effects of the stage of flower development and anther dehiscence were assessed on both pre-and post-cryopreservation viabilities. Successful long-term storage of pollen will facilitate hybridisation of rose species and cultivars that do not flower synchronously. 相似文献
82.
Pollen characteristics, inheritance and allelism of 23 genetic male-sterile (ms) mutants of rice (Oryza sativa L.) were investigated. Ten of the mutants were induced by ethyl methane sulfonate, one induced by ethyleneimine, seven induced by gamma rays, one induced by streptomycin, one derived from tissue culture and three were spontaneous mutants found in the field. Four pollen abortion types were observed among these ms mutants: 3 no-pollen (NP) type, 6 complete pollen abortion (CPA) type, 13 partial pollen abortion (PPA) type, and 1 stainable pollen abortion (SPA) type. Progeny tests over two years indicated that each of the mutants was inherited as a monogenic recessive. A partial diallel cross among the 23 ms mutants indicated that mutant E2 was allelic to G4, E5 was allelic to E9, N2 was allelic to N3, and that three other mutants, E3, G6 and T1, shared the same ms locus. Gene symbols ms-46 (t) through ms-63 (t) were assigned to these mutants. 相似文献
83.
C. Lanaud 《Plant Breeding》1987,99(3):187-195
Ovule and pollen fertility have been studied in doubled haploids of cocoa derived from spontaneous haploids, doubled by colchicine treatment. The two measures of fertility were very variable; occasionally, the levels were as high as those of the parent plant, but most were lower. The low fertility was not improved either by changing pollinators or after grafting. Pollen fertility also varied seasonally more in doubled haploids than in their parents. The lack of differentiation of embryo sacs seemed to be the cause of low values of ovule fertility. Both of these unfavourable characteristics were not observed in the progeny of doubled haploids, The low fertility is described in terms of homozygote depression, forced, on normally allogamous plants, its consequences for the use of doubled haploids in the production of hybrid seeds are discussed. 相似文献
84.
转Bt-cry1Ab玉米花粉对意大利蜜蜂生长发育及体内酶活性的影响 总被引:2,自引:0,他引:2
自10年前首次种植转基因植物以来,转基因作物已在全球得到大面积推广。这些转基因作物中绝大多数品种具有抗虫基因能够增强作物对靶标昆虫的抗性。同时转抗虫基因植物可能带来的生态安全和环境问题也引起了国际社会广泛的关注。鉴于此,本实验开展了转Bt-cry1Ab基因抗虫玉米花粉 相似文献
85.
Hiromitsu Samejima Marfaizal Marzuki Teruyoshi Nagamitsu Tohru Nakasizuka 《Biological conservation》2004,120(4):577-587
Human disturbance of tropical rainforests may change pollinator communities indirectly as a result of changes in resource availability. We studied the mechanisms by which human disturbance affects a community of major pollinators, stingless bees, in Sarawak, Malaysia. We surveyed forest structure and flowering activity, and conducted a nest census and a bait-trap survey of stingless bees, both in primary forests and in forests disturbed by logging and shifting cultivation. The densities of late successional trees and large trees (diameter at breast height >50 cm) were higher in the primary forests than in the disturbed forests. The density of flowering trees was lower one year after logging, but recovered in old disturbed forests because of the active flowering of pioneer trees that became established after the disturbance. Stingless bees nest only in large trees, and nest density was positively correlated with the density of large trees. However, we found no relationship between the numbers of foragers and floristic parameters. Some species preferred nesting in dipterocarps, while others preferred dead trees. The results of the bait-trap survey also indicated that some species were abundant in the primary forests, whereas other species were abundant in the disturbed forests. These results suggest that human disturbance alters the species composition of the stingless bee community. Such changes in the bee community may affect the reproductive success of plants, and ultimately forest composition. 相似文献
86.
87.
Shunhua Yang Shangkao Deng Haiou Kuang Danyin Zhou Xueyang Gong Kun Dong 《Journal of insect science (Online)》2021,21(4)
The hexagonal structure of the honey bee comb cell has been the source of many studies attempting to understand its structure and function. In the storage area of the comb, only honey is stored and no brood is reared. We predicted that honey bees may construct different hexagonal cells for brood rearing and honey storage. We used quantitative analyses to evaluate the structure and function of the natural comb cell in the Chinese bee, Apis cerana cerana and the Italian bee, A. mellifera ligustica. We made cell molds using a crystal glue solution and measured the structure and inclination of cells. We found that the comb cells of A. c. cerana had both upward-sloping and downward-sloping cells; while the A. m. ligustica cells all tilted upwards. Interestingly, the cells did not conform to the regular hexagonal prism structure and showed irregular diameter sizes. In both species, comb cells also were differentiated into worker, drone and honey cells, differing in their diameter and depth. This study revealed unique differences in the structure and function of comb cells and showed that honey bees design their cells with precise engineering to increase storage capacity, and to create adequate growing room for their brood. 相似文献
88.
《北京林业大学学报》2012,34(2)
采用细胞遗传学方法,对Longiflorum×Asiatic系列异源三倍体百合‘Bonsoir’(2n=3x=36)小孢子母细胞减数分裂进行了研究和分析。结果显示,有64.31%的花粉具有活力,且有活力的花粉大小范围在986.33-3491.68μm2之间,并呈双峰分布。形成败育花粉的主要原因如下:高度不规则的染色体配对、落后染色体、染色体桥、不均等分离、微核等现象。另外,减数分裂中期Ⅱ纺锤体的异常定向导致了末期Ⅱ二分体和三分体的形成,产生未减数的配子,如融合纺锤体和三极纺锤体;但平行纺锤体和垂直纺锤体不参与未减数配子的形成。一些小孢子母细胞在胞质分裂过程中未形成细胞板,导致单分体的形成以及二分体和三分体的增加,提高了未减数配子的颛率。通讨对小袍子发毕讨稃中各种观象的观察.对异源=倍体百合存畜种申的府阳讲行讨论. 相似文献
89.
90.
Screening and Analysis of Proteins Interacting with TaPDK from Physiological Male Sterility Induced by CHA in Wheat 总被引:1,自引:0,他引:1
To further research the regulatory network of pyruvate dehydrogenase kinase (designated as TaPDK) in physiological male-sterility (PHYMS) of wheat induced by chemical hybridizing agent (CHA) SQ-1, an anther cDNA library was constructed, and the proteins interacting with TaPDK were screened via yeast two-hybrid technique. Subsequently, a few candidate proteins in nucleotide expression levels were detected by real-time quantitative PCR. Yeast-two hybrid screening was performed by mating yeast strain Y2HGold containing BD-TaPDK bait plasmid with yeast strain Y187 including anther cDNA library plasmid. Diploid yeast cells were plated on synthetic dropout nutrient medium (SD/-Ade/-His/-Leu/-Trp) (QDO), and further were incubated on QDO medium containing AbA and X-α-Gal. The interactions between TaPDK and the proteins obtained from positive colonies were further confirmed by co-transformation validation. After plasmids DNA were extracted from blue colonies and sequenced, the sequences results were analyzed by bioinformatic methods. Finally, 24 colonies were obtained, including eight genes, namely non-specific lipid-transfer protein precursor (TanLTP), polyubiquitin (TaPUbi), glyceraldehyde-3-phosphate dehydrogenase, proliferating cell nuclear antigen (TaPCNA), CBS domain containing protein (TaCBS), actin, guanine nucleotide-binding protein beta subunit, chalcone synthase, and three new genes with unknown function. The results of quantitative RT-PCR showed that the expression levels of TanLTP, TaPUbi, and TaPCNA were obviously up-regulated in PHYMS anther, and TaCBS expression was only increased at the tricellular stage in PHYMS anther compared with in fertile lines. Whereas, the expression of TaPDK was obviously down-regulated in PHYMS lines. Collectively, these datas indicated that the majority of candidate proteins might be related to pollen abortion in PHYMS lines, which further suggested that TaPDK plays multiple roles in pollen development, besides participating in regulating pyruvate dehydrogenase complex activity. 相似文献