夏威夷品種木瓜在臺灣試種與雜交一代之表現

Performances of Hawaiian Papayas and Their First Generations (F1) of Cross Hybrids Grown at Chia-Yi, Taiwan

張振宙(C. C. Chang) ； 吳嘉成(C. C. Wu)

《中華農業研究》 23卷4期 (1974/12) Pp. 273-283

https://doi.org/10.29951/JARC.197412.0005

摘要

民國56年中華民國園藝作物考察團自夏威夷引進其外銷木瓜11品種，經嘉義農業試驗分所試種結果，認爲其中之Kopoho，Sunrise與A5三品種生長與果實品質較優。本研究以此三者爲觀察對象，獲悉臺灣嘉義地區之氣候條件，對夏威夷品種木瓜之影響甚爲嚴重。由於每年自十月開始乾季，氣溫隨之逐漸降低，至翌年一、二月爲最低（常達2°或4℃)；三月中旬氣溫轉暖，五月開始雨季；在此長期乾燥與低溫之雙重影響下，植株生長，嚴重受阻，開花與結果數爲之大減。又自十一月中旬以後至翌年三月中旬以前，平均溫度常在20℃以下，是時Kapoho品種所分化之花芽，具有性變(Sex Change)現象者，高達96%；果實經過低溫期發育者，自開花至成熟需160~237日，在高溫期則祗需132~146日；成熟果實之糖度，在高溫期爲15~17°(Brix)，在低溫期爲9~11°(Brix)，且果實表面常多斑點(Freckles)，果肉中含有硬塊(Lump)，品質低劣，均無市場價值。據本研究結果，夏威夷品種木瓜在嘉義地區之氣候條件下，正常果實之採收期，約爲四個月，僅及夏威夷之三分之一，而正常果實之產量，不及五分之一。
本研究用Kapoho，Sunrise與A5雜交陸，其第一代(F1)之表現爲：(1)植株矮性爲顯性，(2)果肉黃色對紅色爲顯性，(3)果肉含水量高之品種與含水量低者雜交後，第一代(F1)之果肉含水量有減少趨勢。

並列摘要

1. Among the papaya varieties of Hawaiian strains introduced from Hawaii in 1967, the Kapoho, Sunrise and A5 were found to be better in fruit qualities and more suitable to grow at Chia-Yi Agricultural Experiment Station, but each of the three varieties has shown the qualified satisfactions. The Kapoho variety has been, in most time, to have the first fruits very highly setting on the plants attributing to the vigorous growth of the young plants, and the fruits tended to be smaller; The Sunrise variety was to have its fruits with most water content, and the A5 variety, dwarfish in growth, selected from the seeds of some fruit bought in a super market in Honolulu, when the Author was in Hawaii in 1967, has been poor in yield and produced most carpellodic fruits attributing to the influence of the low temperature in the winter at Chia-Yi.
2. The low temperature in the winter at Chia-Yi, has evidently induced the production of sex changed flowers and carpellodic fruits formed on the tree. According to this experiment, it was found that the Hawaiian papayas could produce in the winter of the first cropping year, 27% of pentandria fruits, 69% of carpellodic or deformed fruits and 4% of normal fruits.
3. The fruits matured in 132-144 days since the flowers opened in the warm season, if the fruits developed through a period of cold weather, they would delayed to come to mature and 160-237 days were required.
4. Sugar content of the fruit developed during the cold season tended to decrease from 17-16° Brix to 11-9° Brix, when it matured. Fruits of different varieties had different degrees of diminution of sugar content. The range of diminution of sugar content of the fruits of A5 was 40%; Sunrise, 30%; A5×Sunrise (F1), 36% and Kapoho×A5 (F1), 37%, while that of the varieties grown at Waimanalo, Qahu, Hawaii was 3.5%. Qualities of the fruits with diminished sugar content became much inferior.
5. Hermaphroditic plants of Kapoho variety was found to produce sex changed flowers at any season of the year. The lowest percentage of the sex Changed flowers opened in July was 1.6, while the highest percentage of the sex changed flowers opened in April was 100.
6. Average numbers of the normal fruits of the Sunrise, Kapoho and A, varieties, harvested in the first cropping year were 47.8, 59.2, 46.0 respectively, but the average numbers of the normal fruits of the same varieties with the weights more than 300 grams, or suitable to the requirements of the market were 31.3, 16.0 and 16.0 respectively.
7. Perfomances of the F1 of cross-breeding with the Hawaiian varieties have shown as (1) dwarf in plant growth is dominant, (2) yellow color of the fruit flesh is dominant over the red color, (3) water content of the fruit flesh tended to diminish, when the variety of the lower water content crossed with the variety of the higher water content, (4) fruit size, shape, and yield tended to be intermediate between the parentages, (5) the average numbers of the normal fruits produced in the first cropping year by the varieties A5, Sunrise, A5×Sunrise (F1) and Kapoho×A5 (F5) were 22.0, 34.5, 50.6 and 28.4 respectively. Yield of A5×Sunrise (F1) is better. (6) Shipping qualities of the fruits of A5×Sunrise (F1) and Kapoho×A5 (F1) were about the same as that of the Kapoho variety.