1. Effect of the Concentration of PEG, Temperature and Treatment Duration on Priming Results of Sweet Pepper ‘Shapphire’
Yuan-Chyi Lin1), Yu Sung2) and Woo-Nang Chang3)
1) Graduate student of Department of Horticulture, National Chung-Hsing University, Taichung, Taiwan
2) Associate professor of Department of Horticulture, National Chung-Hsing University, Taichung, Taiwan
3) Professor of Department of Horticulture, National Chung-Hsing University, Taichung, Taiwan
Summary
Osmotic conditioning of sweet pepper (Capsicum annuum L.) ‘Shapphire’ seeds by polyethylene glycol (PEG ) 6000 showed that primed seeds germinated and emerged more rapidly than untreated ones in both laboratory and field tests. The time to 50% of final germination (GT50) and time to 50% of final germination and emergence (GT50 and ET50 ) of primed seeds reduced by 5.24 to 1.23 days (GT50) and 7.74 to 2.78 days (ET50), respectively. Priming did not significantly shorten the spreading time of 10 to 90% of final germination and emergence (GT90 - GT10 and ET90 - ET10) for ‘Shapphire’ seeds. Interaction effects among priming concentrations, temperatures and treatment duration were significant on seed vigor. Second order response surface regression model could demonstrate the variation trend of seed viability after priming for cultivar ‘Shapphire’. The optimum priming conditions were -0.7 ~ -1.0 Mpa PEG, 17~23℃ and 4~7 days for ‘Shapphire’ seeds.
Key words: Sweet pepper (Capsicum annuum L.)、Osmotic conditioning、Uniformity of germination
Effects of Medium Composition and Temperature on Pollen Germination of
‘Cariflora’ Papayas (Carica papaya L.) Zen-hong Shu Department of Plant Industry, National Pingtung University of Science and Technology, Pingtung 912, Taiwan SummaryThe study was aimed to find out the optimal in vitro pollen germination condition of ‘Cariflora’ papayas as well as if low and excessively high temperatures being the cause of the low fruit setting problem of the net house-grown papayas in Taiwan. The optimum in vitro germination condition for fresh ‘Cariflora’ pollen was observed on 100 mg/l H3BO3, 200 mg/l MgSO4.7H2O, 300 mg/l Ca(NO3)2 .4H2O and 100 mg/l KNO3, with 2.5 % polyethylene glycol (PEG), 2.5 % sucrose and 0.2 % agar. Optimum pH ranged between 5-6 and temperature between 30-40 ℃. The germination percentage under 20 ℃ was only about 28 % of that at 35 ℃ and pH 5.
Key words: optimum condition, pH, temperature
Dormancy and Germination Promotion of Viburnum odoratissimum Seeds
Shun-ying Chen1）, Ching-te Chien1,2）, Yu-cheng Chen1） and Wan-long Chang1）
1) Taiwan Forestry Research Institute.
2) Corresponding author, 203 Kung-yuien Road, Heng-chun, Ping-tung, Taiwan
Summary
The freshly mature seeds of Viburnum odoratissimum Ker. - Gawl. germinated poorly due to dormancy. The seed dormancy could be broken by a cold or combined warm and cold stratification. Fresh seeds of V. odoratissimum were stratified at 5 ℃ for 2 to 3 months and then incubated at alternating temperature of 25/15℃ for germination. In addition to increase germination percentage of seeds, the cold stratification reduced time of first radicle protruding and resulted in complete germination within eight weeks. The combination of warm and cold stratification was that fresh seeds were placed at alternating temperature of 30/20℃ for 1 month followed by 5℃ for 2 to 3 months. The method was enough to release Viburnum seed dormancy and promoted germination.
Key Words: Viburnum odoratissimum, seed dormancy, seed germination, combined stratification, cold stratification
Effects of Mother Plants Propagated in vitro on Rooting of Chrysanthemum Cuttings in vivo
Shwu-Fen Chang1) and Min-Chang Huang2)
1) Assistant, Taiwan Seed Improvement and Propagation Station, Taichung, Taiwan,
2) Professor, Department of Horticulture, National Chung-Hsing University, Taichung,
Taiwan
The rooting of cuttings from the mother plants or from regenerated plantlets of chrysanthemum [Dendranthema ×grandiflorum (Ramat.) Kitamura] ‘Huang Shiu Fang’was compared. The total root length, the number of roots and the fresh weight of the cuttings from regenerated mother plants were better than those from cuttings. However, this tendency was decreased by propagation generation. Until the forth cutting, the total root lengths of cuttings from regenerated plants were still longer than those from cutting plants.
Key words: Dendranthema ×grandiflorum, micropropagation, cutting.
Effect of seedling age on growth characteristics of transplanted chili pepper (Capsicum annum L.)
Y.C. Shih 1）, S.J. Tsao 1）, M.C. Tseng 2）
Department of Horticulture 1）and Dept. of Agronomy 2）, National Taiwan University, Taiwan
Summary
Various growth characteristics were evaluated on chili pepper (Capsicum annum L., ‘Ever-flavor’) seedlings of different ages at and after transplanting. The seedling age was counted as days after cotyledon unfolding, six seedling ages, i.e. 30, 34, 38, 42 and 46 days in spring and 24, 28, 32 and 36 days in fall were evaluated. The relative seedling index and average daily growth (G value) of spring and fall chili pepper were similar and ranged between 0.04-0.08 and 3.4-5.3 mg day-1, respectively. The seedlings over 42 days of age had a reduced G value in spring. The leaf area ratio was 300 for seedlings of 30 days of age and decreased for older seedlings. The relative growth rate (RGR) of plant dry weight was highest for seedlings of 30 days of age at the first week of transplanting (WAT). No significant difference was observed at 2 WAT for all ages of seedlings. Lower RGR was obtained in 46-day seedlings at 4 WAT. In fall, younger seedlings of 24 and 28 days of age had higher RGR than seedlings of 32 and 36 days of age. No significant difference was observed at 3 WAT for all ages of seedling. The younger seedlings flowered later than older seedlings of 32 and 36 days of age by 7 days. However, all seedlings had the same first flowering node, early yield and total yield. The best seedling age for chili pepper transplants was not beyond 42 days in spring and between 24-36 days in fall.
Key word: seedling age, chili pepper(Capsicum annum L.), seedling quality, plug seedling.
Influence of Water Supply on Plug Seedlings of Cabbage and Tomato
Yung-Wei Sun
Taiwan Seed Improvement and Propagation Station, Shin-shie, Taichung, Taiwan
Summary
The objectives of this research were to study the effects of water supply to structure of cabbage (Brassica oleracea L. Capitata group) and tomato (Lycopersicon esculentum Mill.) seedling on plug system, and to study relationships between water supply and evapotranspiration rate with temperature in greenhouse. The results indicated that cabbage plug seedlings grew slowly and required much more water than tomato. Media water content maintained in the range of 160-260% for cabbage seedlings resulted in good plant height, shoot and root dry weight, and survival rate. Plant height, shoot and root dry weight can be used as seedling index of cabbage seedlings. Media water content at 130-180% was more effective for tomato seedlings. The ratio of shoot dry weight and plant height could be used as a proper seedling index of tomato seedlings. A positive correlation existed between irrigation and evapotranspiration. The ratio of accumulated evapotranspiration and accumulated irrigation showed a relative high evapotranspiration in low irrigation. There was a positive correlation between temperature of greenhouse and evapotranspiration of irrigation treatments. The temperature data recorded in greenhouse can be used to predict evapotranspiration of plug seedlings.
Key words: irrigation, evapotranspiration, seedling index, crop water stress index,