台木品種の違いが水ナス果実の果皮および果肉の硬さに及ぼす影響(栽培管理・作型)  [in Japanese] Influence of Rootstock Cultivars on Firmness of Skin and Flesh of 'Mizunasu' Eggplant Fruit(Crop Production & Cropping Type)  [in Japanese]

台木品種の違いが,'水ナス'の果皮と果肉の硬さに及ぼす影響について検討した.台木品種として,'レトロ','ヒラナス'および'AE-RS01'を供試した.果実赤道部より直径19mm厚さ10mmの果皮付き試験片を調整し, 直径1.5mmφのディスク状の感圧軸を果皮側および果肉側から貫入速度20mm/minで貫入させた.果皮側貫入および果肉側貫入のいずれの試験結果からも,'トレロ'を台木として生産された'水ナス'の果実の果皮および中果皮は硬くなることが明らかとなった.果肉の硬さについては,貫入方向によって結果が異なった.供試した台木品種の中では,'トレロ'が穂木の生育を最もおう盛にする台木であり,'水ナス'では草勢が強くなる台木を利用すると果皮および中果皮が硬くなると考えられ,台木品種選定時には注意を要すると考えられた.

The influence of rootstock cultivars on the skin and flesh firmness of eggplant fruit was examined. 'Mizunasu' was grafted to three kinds of rootstock cultivars, 'Torero', 'Hiranasu' and 'AE-RS01'. The samples 19 mm in diameter and 10 mm thickness including skin were prepared for puncture test using the universal testing machine, Instron 5540. A disc shaped plunger 1.5 mm in diameter punctured the samples at a speed of 20 mm per minute. The samples were punctured in both a centripetal direction (through the skin into the flesh) and a centrifugal direction (through the flesh against the skin). In both directions, the skin of the fruit was significantly firmer in 'Mizunasu' grafted to 'Torero' (M/T) than in 'Mizunasu' grafted to 'Hiranasu' (M/H) or in 'Mizunasu' grafted to 'AE-RS01' (M/A). The results of flesh firmness differed according to the puncture directions. The M/T plants showed more vigorous growth than the M/H or M/A plants. It was considered that 'Mizunasu' grafted to vigorous rootstock cultivar produced fruit with a firm skin.