To prove the androgenic origin of the regenerants obtained from the anther cultures of interspecific F 1 C. annuum L. ATZ1 × C. frutescens L.) hybrid, Random Amplified Polymorphic DNA (RAPD) method was applied.Thirty decamer primers were used in the experiment. The size of the amplified products ranged from 138 to 2369 bp, and their number from 3 to 25 per primer. About 274 loci, 47 of which were polymorphic, were analyzed. The results proved the hybrid status of anther donor plants detected by 20 of the applied primers. Of the 25 analyzed androgenic regenerants, 18 were diploids. The RAPD reactions confirmed their polymorphism in comparison with that of the F 1 hybrid generation, which excluded their origin from somatic cells of the anthers. Moreover, the results demonstrated the existence of a genetic variation among the obtained haploids, which illustrated genetic diversity of the microspores developing in hybrid anther cultures. The results of the experiments proved the utility of the RAPD method in detecting polymorphisms between closely related pepper plants, proving at the same time the effectiveness of androgenesis, regeneration of haploid plants, and spontaneously doubled haploids (DH lines).
In research on androhaploids in the progeny of interspecific hybrids within the Capsicum genus, three genetically stable lines of F 7 generation, selected from the C. annuum L. 9 C. chinense Jacq. hybrid, were used. In the first line, only callus tissue was formed as a reaction to the conditions of culture. Cytometric analysis of this tissue revealed the presence of cells with DNA content in nuclei at the level of 1C to 16C. The tissue was mixoploid and non-embryogenic. Anthers of the other line did not respond. In the third one, nine embryos were obtained, and they developed into plants. By means of cytometric analysis, the 1C DNA level was found in eight of them and these were androgenic plants. The origin of one of the diploid plant was not established due to the homozygous character of the donor plants. The experiment results confirm the already known diversity of genotype reaction to the conditions of culture. It moreover point to the possibility of selection of the forms with an androgenic potency from interspecific hybrids.
Summary
In the research on induced androgenesis, eight groups of plants, the progeny of interspecific hybrid of Capsicum frutescens L. x C. annuum L., were used. Half of them were standard hard-flesh forms, while the others have represented SS or Ss genotype conditioning the soft flesh of ripe fruit. Anthers from the plants of six groups produced mixoploid callus and the DNA content ranged from 1C to 16C. Three groups formed embryos which converted into plants. The total number of regenerants was 19, included both androgenic haploids (13) and diploids (6). The results did not allow to present the simple relationship between the physiological feature of soft-flesh and the effectiveness of androgenesis. Pungent, soft-flesh genotypes appeared as a poor responsive in anther culture. The R2 and R3 generation of two soft-flesh diploids, evaluated in two-year experiments, showed full phenotypic uniformity, proofing the androgenic origin of diploids. These DH lines were different with regard to capsaicinoid profiles. The content of capsaicinoids ranged from 0.056 to 2.170 and from 0.019 to 1.610 g*kg-1 for capsaicin and dihydrocapsaicin, respectively. The highest concentration of the compounds was observed in the placenta. Although the androgenic effectiveness was not fully satisfactory, the doubled haploid technology can be used for the rapid genetic stabilization of soft-flesh Capsicum spp. recombinants and the special attention should be paid to the spontaneous androdiploids.
SummaryThe present research involved the evaluation of relationships between technological characters of soft-flesh fruit in the lines derived from the hybrid Capsicum frutescens L. x C. annuum L. The evaluation was performed in groups of genotypes which differed in their fruit weight and pericarp thickness. The material researched was made up of the pericarp from which placenta with seeds was removed and the puree obtained as a result of whole fruit crushing. The analysis of the content of capsaicinoids was made using the HPLC method. The content of capsaicin was in each case higher than that of dihydrocapsaicin. There were observed highly significantly positive correlations between the average fruit weight and the wall thickness in the genotypes of a higher level of these characters, namely in the groups over 20 g (fruit weight) and over 3 mm (wall thickness). In these groups the content of capsaicinoids was negatively correlated with the average fruit weight. The significance of this relationship was confirmed in the genotypes of a higher fruit weight as compared with the content of capsaicin and dihydrocapsaicine in the puee. The relationships between the capsaicinoids researched were more stable in the genotypes of a higher fruit weight and demonstrating a higher pericarp wall thickness.
The aim of the study was to determine the effect of 2,4 D (2,4di-chlorophenoxyacetic acid) used separately and in a mixture with BAP (benzylaminopurine) on fertility and some features of tomato fruit. The plant flowers were immersed only once in water solutions of the growth regulators (2,4 D 0.001%; 0.005 %; 2,4 D 0.001% + BAP 0.001%; 2,4 D 0.005 % + BAP 0.005 %). The mean fruit weight, fruit volume, specific weight, and the jelly weight were determined. The number of seeds collected from the fruit was used as a criterion of fertility estimation. No statistically significant differences were tbund in the mean fruit weight, fruit volume and specific weight. The fruits derived from the plants which were not exposed to the action of growth regulators were characterized by the smallest amount of jelly while the fruits set under the influence of 0.001% 2,4 D + 0.001% BAP had the largest jelly amount. The greatest differentiation was found in fertility which ranged from 7.5 seeds from the fruit derived from the plants treated with 0.005 % 2,4 D, to 75.7 seeds from the non-treated plants' fruit. The BAP addition caused the limitation of fertility reduction.
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