Seedless fruit production in eggplant (Solanum melongena L.) by using plant growth regulators and colchicines

本試驗目的為研究生產茄子無子化果實之可行性，將以三種果形之茄子進行GA與Auxin類生長調節劑之不同藥劑濃度、施用方法、次數處理，以期選出其最適之方式，促進單為結果，提供日後茄子無子化果實生產之參考。另研究秋水仙素誘導茄子多倍體化之最佳方式及鑑定多倍體方法，並進行茄子三倍體之育種試驗，以期達到略精結實。 以不同濃度之NAA及2,4-D於開花當日分別處理除雄及未除雄之茄子子房，‘麻芝茄’以除雄加上10 mg l-1 2,4-D處理之果重及無子果實率最佳，分別為90.9 g、76.2%。未除雄以10 mg l-1 2,4-D 、100 mg l-1 NAA處理之果重174.5及176.8 g最佳。‘粉紅佳人’以未除雄、10 mg l-1 2,4-D處理之果重231.4 g最好，無子果實率以除雄加上100 mg l-1 NAA之80.6%最佳，施用生長調節劑增加可收果數。‘紫水’ 果重無論除雄或未除雄，皆隨生長調節劑濃度提高而增加，其無子果實率介於47.6-60.3%，處理間無顯著差異。施用方法上，‘麻芝茄’ 果重及果實生長情形以浸漬效果最佳。‘粉紅佳人’以噴灑對果重最佳，生長情形以滴之表現最佳、‘紫水’ 果重及果實生長情形以羊毛脂膏塗抹方式最佳。於無子化果實生產上， GA以200 mg l-1之效果最佳，Auxin類之生長調節劑處理最適種類及濃度，分別為‘麻芝茄’10 mg l-1 2,4-D、‘粉紅佳人’5 mg l-1 2,4-D、‘紫水’150 mg l-1 NAA，可得最少種子數及最高無子果實百分率。 茄子多倍體誘導上以秋水仙素混和展著劑後，進行生長點處理，‘麻芝茄’以0.2%之誘導率為41.7%。‘粉紅佳人’誘導率為50%，提高處理濃度其誘導率無顯著變化，‘昭君’則以0.4及1%秋水仙素之75%效果最好。四倍體之葉部型態、花器、氣孔、花粉及植株型態的大小或數量皆大(多)於二倍體者。以流式細胞儀檢測倍數體情形，‘麻芝茄’之多倍體率介於58.3-91.7%，嵌合體介於8.3-16.7%，與染色體鏡檢之41.7-66.7%及16.7-41.7%之結果不符。‘粉紅佳人’以流式細胞儀及染色體鏡檢之結果比較，前者之四倍及嵌合體分別介於16.7-75%、8.3-50%，後者為8.3-58.3%、25-66.7%。‘昭君’經由誘導後為四倍及嵌合體之比率分別為58.3-83.3及8.3-25%，以染色體鏡檢後則減少至41.7-75%和16.7-41.7%。三倍體育種試驗，以‘粉紅佳人’四倍體作為母本，授以二倍體植株之花粉，可獲得三倍體之茄子種子，且種子發芽率可達73.3%。三倍體植株栽種於田間，皆可有效座果、果實發育，但果實皆較二倍體之果實小，果長、寬分別為6.7 cm及2.8 cm，果實內部無種子產生。 本研究以生長調節劑誘導單為結果或三倍體茄子之略精結實，皆可達到無子化茄子果實生產之目的。The purpose of this study was to develop procedures to grow seedless fruit of the eggplant and use the results as a reference for practical production on the farm. In order to discover the optimal feasible procedures to induce parthenocarpy, three cultivars of eggplant were treated with plant regulators (including GAs and auxins) at differing concentrations using different treatment methods and frequencies of treatment. In addition, colchicines was used to induce polyploidy in the eggplant, and a method of identifying differing polyploidy was established for the development of triploid offspring. On the date of flowering, different concentrations of auxin (NAA and 2,4-D) were used to treat the ovaries of the emasculated or unemasculated flower. The results showed that the best seedless fruit production was obtained from emasculated flowers upon treatment with 10 mg l-1 2,4-D, resulting in a fruit weight of 90.9 g and a seedless rate of 76.2% for ‘Matsu'; while fruits obtained from unemasculated flowers exhibited the best production rate upon treatment with 10 mg l-1 2,4-D and 100 mg l-1 NAA, resulting in a fruit weight of 174.5 and 176.8 g, respectively. For ‘Pink Diana', fruits obtained from emasculated flowers exhibited the best fruit weight upon treatment with 10 mg l-1 2,4-D and the best seedless rate of 80.6% upon treatment with100 mg l-1 NAA and the number of harvestable fruits was increased with the use of growth regulators. ‘Shisui' cultivar, fruit obtained from emasculated flowers had a seedless rate in the range of 47.6-60.3%, but no significant differences were seen with different concentrations of growth regulators. In addition, the fruit weight increased with an increasing concentration of growth regulators in both emasculated and unemasculated flowers. In terms of the treatment method, in order to produce more seedless fruit, the best methods of application of growth regulators to the plants were spraying and dropping for ‘Matsu', spraying for ‘Pink Diana', and lanolin paste for ‘Shisui'. For GAs, a concentration of 200 mg l-1 resulted in the best seedless rates in all cultivars. For auxin, the best concentrations and type of auxin in order to obtain the lowest total seed number and the highest percentage of seedless fruits for ‘Matsu', ‘Pink Diana', and ‘Shisui' were 10 mg l-1 2,4-D, 5 mg l-1 2,4-D, and 150 mg l-1 NAA, respectively. For polyploidy induction, colchicines mixed with surfactant was used to treat the shoot apexes. Polyploidy induction with 0.2% colchicines in ‘Matsu' and ‘Pink Diana' was 41.7% and 50%, respectively; and no significant increase in the induction rate was seen with higher concentrations of colchicine. On the other hand, for the ‘Fullness', 0.4% and 1% of colchicines mixed with surfactant resulted in the best induction rate of 75%. The leaf morphology, flowers, and the size and number of stomata and pollen of the tetraploid plants were all greater than those of the diploid plant. In addition, the polyploids of the shoot apexes treated with colchicines mixed surfactant were analyzed by flow cytometry, and the results were as follow in ‘Matsu', flow cytometry analysis showed the percentage of polyploidy to be 58.3-91.7% and chimeras to be 8.3-16.7%, which differed greatly from the actual polyploidy according to microscopic examination (41.7-66.7% and 16.7-41.7%, respectively). In ‘Pink Diana', flow cytometry analysis showed the polyploidy and chimera rates to be 16.7-75% and 8.3-50%, respectively, while the percentages obtained by microscopic examination were 8.3-58.3% and 25-66.7%, respectively. ‘Fullness', flow cytometry analysis showed the polyploidy and chimera rates to be 58.3-83.3% and 8.3-25%, respectively, while the percentages obtained by microscopic examination were 41.7-75% and 16.7-41.7%, respectively. The triploid breeding experiment was performed using tetraploid ‘Pink Diana' as the female parent, which was then crossed with pollen from a male diploid parent. The generated triploid seeds had a germination rate of 73.3%, and had good effective fruit set rates and fruit development in the field on the farm. The fruit of triploids were seedless; however, the fruit length and width were only 6.7 and 2.8 cm, smaller than the diploids. This study used growth regulators to develop triploid offspring by stenospermocarpy in eggplants. The results indicated that the procedures could produce seedless fruits. This will help to overcome and seed hardening and fresh brownization problems.中文摘要 i 英文摘要 ii 表目次................................................................................................... v 圖目次………………………………………………………………………………..vi 壹、前言 1 貳、前人研究 2 一、茄子生長特性及品種分類 2 二、果實發育 3 三、生長調節劑與果實發育 3 四、多倍體育種 6 參、材料與方法 9 一、植物生長調節劑生產茄子無子果實 9 二、茄子多倍體之誘導 11 三、茄子不同倍數體生育比較 13 肆、試驗結果 15 一、植物生長調節劑生產茄子無子果實 15 二、茄子多倍體之誘導 40 三、茄子不同倍數體生育比較 59 伍、討論 62 陸、參考文獻 6