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排序方式: 共有210条查询结果,搜索用时 15 毫秒
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朝阳县棉田棉铃虫1年发生2代,主害代为二、三代。通过对近年来棉铃虫发生情况调查分析,提出种植方式改变、外区域棉铃虫发生重、天敌种群数量减少、偏重药剂防治、轻视诱杀防治是棉铃虫加重发生的主要原因。在棉铃虫综合防治中强调运用应急防治和长期控制相结合的防治对策。 相似文献
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Michael Willmann Emir Hadzijusufovic Olivier Hermine Mauro Dacasto Laura Marconato Karin Bauer Barbara Peter Susanne Gamperl Gregor Eisenwort Erika Jensen‐Jarolim Mathias Müller Michel Arock David M. Vail Peter Valent 《Veterinary and comparative oncology》2019,17(1):1-10
In humans, advanced mast cell (MC) neoplasms are rare malignancies with a poor prognosis. Only a few preclinical models are available, and current treatment options are limited. In dogs, MC neoplasms are the most frequent malignant skin tumours. Unlike low‐grade MC neoplasms, high‐grade MC disorders usually have a poor prognosis with short survival. In both species, neoplastic MCs display activating KIT mutations, which are considered to contribute to disease evolution. Therefore, tyrosine kinase inhibitors against KIT have been developed. Unfortunately, clinical responses are unpredictable and often transient, which remains a clinical challenge in both species. Therefore, current efforts focus on the development of new improved treatment strategies. The field of comparative oncology may assist in these efforts and accelerate human and canine research regarding diagnosis, prognostication, and novel therapies. In this article, we review the current status of comparative oncology approaches and perspectives in the field of MC neoplasms. 相似文献
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Mutations affecting qualitative traits were induced by seed ageing in lettuce. The mutant plants were isolated in the A2 generation and included chlorophyll-deficient types (chlorotica, lutescens, chlorina-virescens, luteo and viridalbo maculate), and morphological variants (dwarf and narrow, thick and curly leaf types). The leaf mutants were found to be either partially or completely sterile. Segregation pattern of the mutants in A3 generation showed that, except for the maculata types, all chlorophyll deficiencies and the dwarf mutant are controlled by single recessive nuclear genes. The genetic status of the leaf mutants was not clear, due to possible pleiotropic effect of the mutant genes in inducing gametophytic sterility. The maculata mutants exhibited sorting out of the normal and chlorophyll deficient regions during vegetative development and segregated for different degrees of chlorophyll deficiency in selfed progenies. The maculata mutants probably originated by plastome mutations induced by nuclear mutator genes. 相似文献
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F. J. Novak S. Daskalov H. Brunner M. Nesticky R. Afza M. Dolezelova S. Lucretti A. Herichova T. Hermelin 《Plant Breeding》1988,101(1):66-79
Sixteen inbred lines and one hybrid of manse were tested for their capability of somatic embryogenesis, and fully developed plants could be regenerated, from ten inbred, lines. The highest frequency of plant regeneration was expressed in the inbred line CHI 31, and when this line was crossed with a recalcitrant, non-regenerating line, the F1 and BC hybrids were regenerable. The results of reciprocal crosses demonstrated that dominant nuclear genes and cytoplasmic factors are primarily responsible for the heritable determination of embryogenic callus proliferation and in vitro regeneration of maize plants. Somaclonal and radiation-induced variability was studied in maize to assess their nature and potential contribution to plant breeding., The inbred line CHI 31 possessing a high in vitro capacity of somatic embryo formation was used as experiments.] material. CHI 31 plants were selfed and twelve-day old zygotic embryos irradiated with 60Co gamma radiation in situ. Mature caryopses were harvested and assigned as M1 material. In another series, immature zygotic embryos (size 1.2—1.5 mm) were cultured in vitro on N-6 medium supplemented with 2,4-D (2.5 μM), and somatic embryos regenerated into plants; these were transplanted into soil and self-pollinated. Regenerants from non-irradiated cultures were grown as R1 generation, while regenerants from irradiated explants were considered as M1R1 generation. The genetic variability was evaluated in the M2, R2 and M2R2 generations, respectively, and compared with a non-treated seed control. Irradiation induced a variety of chlorophyll and morphological variants segregating in the M; generation; however, the frequency of deviant types obtained in the R: generation (somaclonal variation) was significantly exceeding the one derived from the M2 populations. The combination of expert irradiation and in vitro regeneration was most effective for the manifestation of chlorophyll and morphological o if types in the M2R2 generation, and increased drastically the frequency of early flowering variants. Differences in the segregation patterns of mutant phenotypes amonsister somaclones in the R3 and M3R3 generations indicate a different genetic basis, of plants originating from the same explant. This phenomenon suggests a mutational sectoring of the callus during culture. Radiation induced and somaclonal variation exerted a similar spectrum of chlorophyll and morphological deviants. 相似文献
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Summary In the period 1980–1984 about 70000 selfed seeds of the petunia cultivar Blue Bedder were treated with the chemical mutagens ethidium bromide (EB) and ethylnitroso urea (ENU) with the intention to induce (new sources of) cytoplasmic male sterility (CMS). This work resulted in 27 stable male sterile MS-plants, all derived from the ENU-treatments.Crosses with the normal fertile type and with material carrying restorer genes for the common type of CMS in petunia were made. Results obtained from some MS-plants raise a presumption of genic male sterility, probably of the dominant type, having been induced. More detailed investigations are underway. 相似文献