Sadami Miyazaki

Successful interspecific hybridization between Cucumis sativus L. and C. hystrix Chakr.

Interspecific F1 hybrids were obtained from a cross between Cucumis sativus L. (2n = 2x = 14) and C. hystrix Chakr. (2n = 2x = 24). Controlled crossing resulted in fruit containing embryos which were excised and rescued on a Murashige and Skoog solid medium. A total of 59 vigorous plants were obtained from a fruit containing 159 embryos (37.3% regeneration rate). Hybrid plants were morphologically uniform. The multiple branching habit, densely brown hairs (especially on corolla and pistil), orange-yellow collora, and ovate fruit of F1 hybrid plants were similar to that of the C. hystrix paternal parent. While appearance of the first pistillate flower was more similar to that of C. sativus maternal parent than to C. hystrix, staminate flower appearance was mid-parent in occurence. The diameter and internode length of stem, shape and size of leaves and flowers were intermediate when compared to the parents. An elongated green, trilobate style/stigma which was not apparent in either parent was observed in staminate flowers of F1 plants. Similarly, the style/stigma of pistillate flower of F1 plants were longger when compared to their parents. The brown pubescence observed on pistillate flowers of the F1 and C. hystrix was not observed on the C. sativus parent. The somatic chromosome number of F1 plants was 19. Two morphologically distinct groups of chromosomes were observed in the F1 hybrid; 7 relatively large chromosomes characteristic of C. sativus, and 12 smaller chromosomes characteristic of C. hystrix. Analysis of malate dehydrogenase isozyme banding patterns provided additional comfirmation of hybridity. Reciprocal crossing of F1 plants to either parent and self-crossing indicated that the hybrids were male and female sterile.

Polyphenol production in hairy root cultures of Fragaria x ananassa

Abstract Hairy roots of Fragaria × ananassa cv. Reikou, induced with Agrobacterium rhizogenes ATCC 15834, grew well in hormone-free Murashige-Skoog (MS), root culture and Gamborg B5 liquid media. Particularly, in MS medium, hairy roots whowed maximum growth (539 mg per flask, dry wt at week 8) producing high contents of polyphenols (especially (+)-catechin (0.59% dry wt at week 8) and procyanidin B-3 (0.80% dry wt at week 7). Polyphenol contents in the intact plant (leaf blade, petiole, calyx, receptacle and root) were also investigated.

Biochemical affinities between Cucumis hystrix Chakr. and two cultivated Cucumis species (C. sativus L. and C. melo L.) based on isozyme analysis

Isozymes of eight enzymes in Cucumis hystrix Chakr. and two cultivated Cucumis species (C. sativus L. and C. melo L.) were analysed electrophoretically to investigate the biosystematics of these three species. Cluster analysis using data from six enzymes indicated that considerable genetic distance existed between both C. hystrix and melon and between C. hystrix and cucumber. C. hystrix might be a key species for studying the evolution and taxonomy of genus Cucumis.

Genetic analysis of phosphoglucoisomerase isozymes in cultivated and wild species of section Cepa in Allium

Phosphoglucoisomerase (PGI) was studied to establish the genetic system of the isozymes in section Cepa of Allium. The results of isozyme analyses using 15 cultivars and clones in two cultivated species A. fistulosum and A. cepa, eight strains in four wild species A. altaicum, A. galanthum, A. oschaninii and A. vavilovii and a total of 10 hybrids between A. fistulosum and A. cepa and between the cultivated and wild species revealed that: 1) PGI was a dimeric enzyme; 2) the two cultivated and four wild species had a common gene locus Pgi-1 where six alleles were identified; and 3) A. fistulosum had Pgi-1F-1 and Pgi-1F-2, A. cepa had Pgi-1A-1 and Pgi-1A-2, A. altaicum had Pgi-1F-1, A. galanthum and A. vavilovii had Pgi-1A-1, and A. oschaninii had Pgi-1A-1, Pgi-1O-1 and Pgi-1O-1. The intra- and inter-specific polymorphisms of PGI isozymes are expected to be valuable tools for the genetics and practical utilization of the wild species in section Cepa.