The Relation between Flowering Period and Seedless Fruits Formation of Irwin Mango (Mangifera indica L.)

愛文檬果(Mangifera indica L.)所發生的無子果體積與重量均較正常果為小，但其果肉與種殼的比率為正常果的3.14倍。在玉井檬果專業區同一果園不同坡向會影響無子果產生，在北坡向無子果的發生率為南坡向的7.23倍，依開花期間兩坡向之溫度比較,北坡向溫度較低可能是造成此一差異的主要原因。 在開花始、中期(12月～3月)氣溫偏低(18.7℃以下)且多雨，完全花與雄花之機能雄蕊花粉生成率很低，此一期間著果的花序無子果發生率高；而開花終期(4月)溫度升高(高於20℃)，花粉生成率高，著果枝條之無子果發生率變低。 完全花經人工除雄控制授粉，包括除雄袋不授粉、同品種及不品種間之混合授粉，採得成熟果實皆為無子果，人工授粉並不能確保正常果的產生，足見溫度在無子檬果之形成上較授粉更具影響作用。 The volumn and weight of seedless Irwin mango were less than those of noumal fruits, but the pulp/stone ratio of the former was 3.14 times of the latter. Study at one orchard at Yu-Ching of Tainan indicated that different slope direction influenced the formation of seedless fruits. The number of seedless fruit formed on northern slope direction were 7.23 times more than that of the southern one. From the study of temperature record, the formation of more seedless fruits on the northern slopeland seemed to be correlated to the generally lower temperature than the southern slope during flowering period. In early and middle part of the flowering period (from December to March), the lower temperature (20℃), functional pollen formed, with very few seedless fruits produced. Perfect flowers were emasculated and followed either by no pollination or pollination with bulk pollen collected from same variety or from different varieties. Whether pollinated or not, all fruits harvested were seedless. This indicates that artificial pollination does not quarantee the formation of normal fruits. The temperature effect seems to be more responsible than pollination for the formation of seedless mango fruit

Pre-harvest sprouting in pecans

Typescript (photocopy).The temperature effect on germination response and physiological activities were compared between sprouting resistant northern pecan [Carya illinoensis (Wang) K. Kock] cultivars and sprouting susceptible southern cultivars. The sprouting resistant character of northern cultivars was incorporated into sprouting susceptible southern cultivars to alleviate a pre-harvest sprouting of pecan. The germination of 'Cherokee' and 'Wichita' were more rapid than 'Johnson' when nuts were incubated at 27° and 34°C. When nuts were incubated at 20°C, the southern and northern cultivars germinated at approximately 20% and 1.5% respectively. The delayed germination characteristic of northern cultivars proved to have excellent potential as a screening method for measuring pecan vivipary. Total lipid content of southern cultivars decreased 17.51% in 'Cherokee', 5.2% in 'Wichita', and did not change in 'Johnson' and 'Pawnee' during germination. The lipids gradually decreased with a concomitant increase in total sugar and reducing sugar. The compositional changes were accompanied with an increasing germination percentage in the southern cultivars during 40 days of germination. However neither compositional change nor germination percentage was changed in 'Johnson' at 20°C and 27°C during 40 days of germination. Immature embryos of open-pollinated seeds of 'Wichita' were excised from ovaries 132-139 days after pollination and grown on different levels of ABA and GA at 20°, 27°, and 34°C to evaluate temperature and growth regulator effects on embryo growth and development.

Pre-harvest sprouting in pecans

Typescript (photocopy).The temperature effect on germination response and physiological activities were compared between sprouting resistant northern pecan [Carya illinoensis (Wang) K. Kock] cultivars and sprouting susceptible southern cultivars. The sprouting resistant character of northern cultivars was incorporated into sprouting susceptible southern cultivars to alleviate a pre-harvest sprouting of pecan. The germination of 'Cherokee' and 'Wichita' were more rapid than 'Johnson' when nuts were incubated at 27° and 34°C. When nuts were incubated at 20°C, the southern and northern cultivars germinated at approximately 20% and 1.5% respectively. The delayed germination characteristic of northern cultivars proved to have excellent potential as a screening method for measuring pecan vivipary. Total lipid content of southern cultivars decreased 17.51% in 'Cherokee', 5.2% in 'Wichita', and did not change in 'Johnson' and 'Pawnee' during germination. The lipids gradually decreased with a concomitant increase in total sugar and reducing sugar. The compositional changes were accompanied with an increasing germination percentage in the southern cultivars during 40 days of germination. However neither compositional change nor germination percentage was changed in 'Johnson' at 20°C and 27°C during 40 days of germination. Immature embryos of open-pollinated seeds of 'Wichita' were excised from ovaries 132-139 days after pollination and grown on different levels of ABA and GA at 20°, 27°, and 34°C to evaluate temperature and growth regulator effects on embryo growth and development.

Characterization and Correlation Study in Mume Cultivars

台灣中部低海拔地區果梅八個栽培種的花期調查，其始花期爲12月下旬至1月中旬，盛花期爲1月上旬至2月中旬，果實採收期於3月下旬開始至5月上旬結束。梅不同栽培種在自然雜交授粉下，著果率可達29.2%~56.9%，依品種而異。 果實性狀主要調查外觀、果肉、核及核仁等可測量與不可測量的性狀共計27個項目。同時利用變方分析探討供試品種間的葉片與果實性狀間的差異性，發現品種間葉片重、葉面積、葉寬、果重、種子重、果高及果寬等差異性皆非常顯著。 葉片與果實性狀間的相關性分析：葉片重與葉面積的相關性爲0.94，與果重的相關性爲0.80，與種子重的相關性爲0.72，且其相關都達非常顯著的水凖。由試驗結果顯示：凡植株葉片重超過0.47g以上者，其果重可達20g。此一結果可用於實生苗早期篩選，以提高選獲大果種的機會。 Bloom data of eight mume cultivars was investigated in the middle part of Taiwan. Date of start bloom occurred from the end of December till middle of January. The full bloom period began in early January to middle February. Season of available maturity for picking started from the end of March and finished at early of May. Fruit setting percentage of mume cultiavars under natural open pollination was varied from 29.2 % to 56.9%. Mume fruit involving 27 measurable and unmeasured characters were detected and described in the experiment. Biostatistics was used to determine the difference between leaf character and fruit character among the eight cultivars. The results indicated that leaf weight, leaf area, leaf width, fruit weight, seed weight, fruit height and fruit width were very significantly different among the cultivars. The test of correlation coefficient between leaf weight and leaf area was estimated to be 0.94. The correlation coefficients among leaf weight, fruit weight and seed weight were 0.80 and 0.72 respectively. These results revealed if a mume plant its leaf weight more than 0.47g may gain a fruit more than 20g. Apply this result to the early stage of seedling selection may increase the possibility of fruit breeding to obtain the larger fruit of new mume cultivar

Heritability and Cultivar Improvement of Walnut

首先比較長山核桃〔pecan, Carya illinocnsis (Wang.) K. Koch〕與波斯核桃(Persian walnut, Juglans reiga L.)兩種作物間生長習性的差異。其次深究遺傳力及核桃18個性狀中，其外表型間的相關性，以尋求直接影響產量高低的主要性狀。從遺傳力的探討中，發現篩選側枝的結實性(fruitfulness of lateral shoots)與側枝的生長勢，是提升核桃產量潛能中的遺傳獲得量(genetic gain)最經濟最有效的方法。而長山核桃則沒有一套經濟有效的育種策略，以致育種成效不彰。核桃育種成功的例子或許可為本省果樹育種研究方向的參考模式。 Different growth habits of pecan and walnut were comparatively studied. Then heritabilities and phenotypic correlations among 18 traits of walnut (Juglans regia L.) were discussed in order to find the main characteristics which directly related to the yield potential. It was found that the most effective and efficient means of improving the rate of genetic gain for yield potential in walnut has been performed by selecting for fruitfulness and vigor of lateral shoots. The successful walnut breeding may provide a model for the fruit breeding program in Taiwan

Breeding Achievements and Future Prospects of Low-chill Peaches in Taiwan

臺灣桃樹栽培生產主要以高山和平地兩種生產類型，政府為減緩高山墾殖對環境所造成的缺失，積極支持桃樹不區化的品種改良研發，營造環境親和型的桃樹永續發展產業。農試所1996年以來以人工雜交授粉19萬以上的花朵，培育近2萬株實生後代。主要育種目標為育成低需冷量、低酸、早熟、大果、外觀鮮豔、品質優良的早、中、晚熟平地水蜜桃新品種。經淘汰選拔，多年來本所已命名推廣’台農甜蜜‘、’春蜜‘、’夏蜜‘及春豐’及‘紅玉’等5個新品種，經品種授權、繁殖及推廣，目前新品種約佔總栽培面的6成以上。為增加桃果實類丑的多樣性，油桃、蟠桃與花果兼用桃將是未來桃樹育種的主要研發目標。因應氣候變遷全球暖化，極低需冷量桃的品種研發，方能滿足暖化環境下樹體休眠的低溫需求，更是平地桃育種的主要核心工作，為臺灣桃樹產業在地化、優質化與多樣化的永續發展奠定根基。 Peach production mainly can be divided in high mountain and low land types of Taiwan. In order to lessen the environmental impact due to high mountain plantation, research finance is supported by the government to develop low-chill peach cultivars for friendly relations to environment and sustainable development of peach industry. More than 189,643 flowers have been hand pollinated and including open pollination totally 19,263 seedlings have been successfully raised since 1996. Peach breeding objectives are to develop low chilling requirement, low acidity, early maturation, large fruit size, attractive appearance, and different ripening stages. Through selection procedure, 5 new low-chill cultivars named ‘Premier’, ‘SpringHoney’, ‘SummerHoney’, ‘Chuenfeng’, and ‘Red Jade’ were registered and released. Cultivation area of thes cultivars reached more than 60% of total production. In order to increase the diversity of peach fruit types, nectarines, flat peaches, and dual purpose (ornamental and fresh consumption) will be the next selection goals. For coping with climate change, very low-chill cultivars need to develop for insufficient chilling requirement during mild winter which will be the core work for peach breeding and being the fundament of localizable, qualitative, diverse, and sustainable development of peach industry

Changes in Flesh Firmness and Ethylene Production of Different Peach Types during Fruit Ripening

為探討臺灣平地桃各栽種果實採後的後熟行為，進行桃不同果肉類型間的果實品質分析、果肉硬度及果實乙烯生成等試驗研究。試驗結果發現硬肉類型(stony hard flesh)與果肉不溶質類型(non-melting flesh, NMF)在貯藏過程中皆維持相當的果實硬度，但前者產生少量的乙烯，後著貯藏後期開始產生大量乙烯。果肉溶質類型(melting flesh，MF)的果實呈現果肉硬度逐日下降並伴隨著乙烯生成量日漸增加或出現生成高峰的現象。由結果顯示硬肉類型的果實後熟行為和果肉不溶質與果肉溶質兩類型明顯不相同。硬肉類型的果肉獨特性狀可供為改良桃的櫥架壽命與貯藏品質的遺傳育種種原。 In order to study fruit ripening behavior of commercial peach cultivar in Taiwan, different peach [Prunus persica (L.) batsch] flesh types were used and evaluated for fruit quality characteristics, flesh firnness and ethylene production. The fruit of stony hard type and non-melting type both remained fruit firmness, but the former very little ethylene production, the later produce many ethylene during end of storage. The fruit of melting type gradually decreasing in flesh firmness was accompanied with an increasing in ethylene production or developing a par during storage. This revealed that the stony hard type follow a different ripening behaviors from melting and non-melting types. The unique flesh trait of stony hard type may be used as a genetic resource for improving shelf life and storage quality

(34(1):33-44)Studies on the Induction of Parthenocarpic Kyoho Grape by Gibberellin Acid and 4-chlorophenoxyacetic Acid

巨峰葡萄於盛花前將花穗浸漬12.5-100ppm 等不同濃度的GA（Gibberellic acid），訂誘發85.3%的無子漿果。GA 處理對果粒重（約6.9g）與小果梗長度之影響較其他植物生長謂節劑為大。盛花後10 天再浸以GA 25ppm 更可明顯地促進果實肥大。 施用12.5-50ppm 等不同濃度的4-CPA ( 4-chlorophenoxyacetic acid ）可誘發98.4 %的無子漿果，但果穗聚密，果粒輕（約3.6g），皺縮果發生率22.2%。 當花穗浸漬等濃度的GA 與4-CPA 混合液（12.5-50ppm），幾乎可誘發100%的無子發生率。無子漿果含糖量最高20.9 oBrix ，皺縮果發生率也高達27.9%，但無子漿果之風味勝過正常有子巨峰葡萄。 在開花枝條上著生從4 至10 葉片等不同生育時期行浸藥處理，發現葉片數愈多，則果粒愈重，糖度也愈高。花穗浸藥前先行疏花處理，其果粒大小與糖度均較不疏花處理者為高，尤其平均粒重可增加44.4%。 果穗重與果實其他性狀間之相關性為：果穗與梗重、粒重與有子漿果數成正相關；與糖度、皺縮果成負相關。 先將花穗下方3-4 個副穗梗及穗軸尖端剪除，然後於盛花前葉片開展至9-10 片時，以各含18.8ppm 的GA 與4-CPA 的混合液浸漬花穗，盛花後10 天以GA 25ppm 第二次行浸漬處理之方法，可以誘發最佳無子漿果。 “Kyoho” grape clusters at pre-bloom stage dipped in GA solution concentrated from 12.5-100 ppm could be induced to produce seedless berries at an average rate of 85.3%. The treatment gave a greater effect on increasing berry weight (ca. 6.9g) and pedicel length than any other treatments did. Effect on increasing berry weight was more significant when an additional dip with 25ppm of GA was added at l0days after full bloom. Application of 4-CPA in a range of 12.5-50ppm also induced seedless berry at a rate of 98.4% however it resulted in a compact clustes, small berries (ca. 3.7g) and shrunken berries (ca. 22.2%). When clusters were treated with mixed GA and 4-CPA in the mentioned concentrations, seedless berries were induced at the rate of almost 100%. The soluble solid content of these berries was as high as 20.9° Brix and shrunken berries occurred at a rate of 27.9%, however seedless berries tasted much better than normal Kyoho berries. The optimum time of dipping treatment would be indexed by the developed leaves on a bearing shoot. When cluster was dipped at the stages with 4-10 leaves, it was found that the more leaves on a shoot, the larger berries with higher sugar content obtained. Thinning flower cluster before dipping increased both berry size and sugar content largely than without thinning. Correlation studies among cluster weight and other fruit characteristics indicated a positive corrleation between the cluster weight and the peduncle, berry size and the number of seeded berries, whereas negative correlation were shown between the cluster weight, and the soluble solids content as well as shrunken berries. The best treatment for inducing seedless “Kyoho” grape was found to be first thinning out the lower three to four branches in the flower cluster and removing the apex of rachis, then dipping the cluster with GA and 4-CPA mix, both at 18.8ppm, at prebloom stage when 9-10 leaves developed on shoot and dipping with 25ppm of GA 10 days after full-bloom again

Physiological Studies on Flowering and Fruiting of Mume Trees

在兩個果梅產品調查果梅開花、果實發育特性並記錄全年果實生長發育期間的溫度變心、調查梅不完全開花的發生頻率，’長藤’最高可達15.8％，少者如’桃形梅’僅有3.0％，發生率高低因品種而異。不完全花其雌蕊長度從0～0.6cm不等，正常花雌蕊之臨界長度約在0.61～0.8cm長的雌蕊發育逐漸趨向正常著果，正常雌蕊最長可達1.35cm。 由果梅三個不同栽培種連續三年產量的綜合變方分析結果得知，不同栽培種於不同年度的產量表現有極顯著的差異，即年度與栽培種間有交感效應存在。年度間產量的顯著差異，表示果梅大小年的現象很明顯。品種間產量的顯著差異，表示果梅產量潛能因品種與株齡而異。 梅開花前的樹體變化調查，其芽體大小與重量在生長季節中變化不大，至8月中下旬以後開始有明顯的變大與變重，至盛花期止。生長季節中梅帶葉枝條含碳水化物的變化趨勢不甚明顯，於10月樹體開始落葉休眠時達最高點，開花前一個月（11月）顯著地降至最低點，而含氮的變化亦以花前一個月（11月）降至最低點，然然再逐漸上升。休眠期間碳水化物與氮與含量減少的趨勢伴隨著芽體的變大與變重。 The blooming, fruit growth and development of mume were studied at two locations during different growth stage and the climatological data were recorded. The occurrence of imperfect flowers in mume varied in cultivars. ‘Chang-teng’ (長藤) which prone to imperfect flower formation had degenerated pistils at a rate as high as 15.8%, while ‘Taur-hsing-mei’ (桃形) had only 3%. The pistil length varied from 0 to 0.6 cm in degenerated flowers. The transitional pistil length for functional flowers was between 0.61 and 0.8 cm. Pistils longer than 0.8 cm developed to set fruit normally. The pistil of normal flower could reach 1.35 cm in length. The yields of 3 different cultivars of mume were investigated for 3 years. The results of combined ANOVA over 3 years indicated significant interaction between years and cultivars. It also indicated the phenomenon of no-year and off-year in fruit production. The significant yield difference among cultivars revealed that the yield potential depended on both the cultivars and age of the plant. During rowing season, the size and the weight of lateral buds of new shoot did not change until late Auguest. In the meantime, the total carbohydrates remaimed almost the same level. A peak occurred in October when buds started dormancy, and a significantly rapid decline followed in November, a month prior to blooming. The pattern of nitrogen change was similar to that of carbohydrates. The decreasing of these two compositional materials was accompanied with the increasing in bud size and bud weight during plant dormancy