Matsumoto H.,Kagawa University |
Seino T.,Kagawa University |
Beppu K.,Kagawa University |
Suezawa K.,Fuchu Branch |
And 2 more authors.
Acta Horticulturae | Year: 2011
Actinidia rufa, native to south western region of Japan, adapts well to warm climates, and has high cross compatibility with diploid A. chinensis kiwifruit. For the purpose of breeding new kiwi-berries adapted to warm conditions, the characteristics of the progenies from interspecific hybridization of A. rufa x A. chinensis (312 plants) and A. chinensis x A. rufa (334 plants) were evaluated. The leaf morphology of the interspecific hybrids was intermediate between the parental species. The flowers of the hybrids were generally larger than those of A. rufa. The fruit of the hybrids have hairless brown skin similar to that of A. rufa, but the green color of the flesh was lighter. The fruit weight ranged from 11.7 to 58.4 g. Phenologically, the interspecific hybrids flowered in early May halfway between A. chinensis in late April and A. rufa in late May. The fruit matured in late October, half a month later than those of A. chinensis and one month earlier than those of A. rufa. The fruit of interspecific hybrids contained total soluble solids (TSS) ranging from 13.5 to 22.0% and titratable acids (TA) from 1.0 to 2.6%. In the interspecific hybrids, total ascorbic acid in the juice ranged from 20 to 70 mg per 100 g FW, higher than in A. rufa fruit which contain about 15 mg. The content of chlorophyll in the fruit flesh was lower in the interspecific hybrids than in A. rufa. Protease activity was detected in the flesh but it was generally low. These results suggest the potential of the interspecific hybrids as the material from which superior clones can be selected.
Kataoka I.,Kagawa University |
Mizugami T.,Kagawa University |
Kim J.G.,Kagawa University |
Beppu K.,Kagawa University |
And 5 more authors.
Scientia Horticulturae | Year: 2010
Survey on the wild genetic resources of hardy kiwifruit (Actinidia arguta) in Japan was conducted to determine the ploidy variation and its geographic distribution. Among the 127 wild plants collected from different geographic locations, 15 plants were diploid, 87 were tetraploid, and 22 were hexaploid. Additionally, 2 plants were heptaploid and one plant was octaploid. The tetraploid plants were distributed all over the country, whereas the diploid and hexaploid plants were geographically localized, in the warm Pacific hill areas of the south western part and in the deep-snow region of the mid-northern part of Honshu, respectively. The diploid plants could be clearly distinguished from other plants with ploidy variation by the morphological characteristics of the leaf and fruit. Hexaploid plants showed a relatively larger L/D ratio of the leaf blade, a greenish petiole, and pubescence on the petiole and lower leaf vein, whereas the tetraploid plants exhibited a reddish petiole and callose hairs on the vein of the lower leaf surface. Fruit shape of the tetraploid plants varied largely, from round to ellipsoidal, whereas that of the hexaploid plants was mostly ellipsoidal. These results indicate that the hexaploid plants of A. arguta as well as the diploid and tetraploid ones, naturally grow in a certain size of population in the restricted region of Japan. © 2010 Elsevier B.V. All rights reserved.
Mworia E.G.,Okayama University |
Yoshikawa T.,Okayama University |
Salikon N.,Okayama University |
Oda C.,Okayama University |
And 6 more authors.
Journal of the Japanese Society for Horticultural Science | Year: 2011
The effects of modified atmosphere (MA) storage and application of 1-methylcyclopropene (1-MCP) at harvest on the storability and quality of 'Sanuki Gold' kiwifruit harvested at two different maturity stages were investigated. MA storage in both fruit harvested early at 136 days after pollination (DAP) or late at 154 DAP delayed flesh softening, increase in soluble solid concentrations (SSC), decrease in titratable acids (TA), and reduction in fruit flesh color index compared to air stored fruit, suggesting that MA storage is effective in prolonging 'Sanuki Gold' kiwifruit storage life. Further, MA stored fruit did not attain full ripening flesh firmness and SSC thresholds even after 4 months of storage under MA conditions, suggesting that early harvested 'Sanuki Gold' kiwifruit can be stored for 4 months in MA. Fruit from both harvesting maturity stages stored under air conditions achieved maximum SSC (18%) values during storage, suggesting that two weeks early harvesting did not compromise edible quality characteristics. Only late harvested fruit treated with 1-MCP and stored in MA showed slight inhibitory effect specific to fruit softening during the first and second month of storage, suggesting that 1-MCP may have some limited ripening inhibitory effect during storage of 'Sanuki Gold' kiwifruit. JSHS © 2011.