Guzmania lingulata (L.) Mez. ‘Cherry’ plants were grown in coconut husk chips. All plants were given 8 mm nitrogen (N), 2 mm phosphorus (P), 4 mm calcium (Ca), and 1 mm magnesium (Mg) at each irrigation with potassium (K) concentration at 0, 2, 4, or 6 mm. After 9 months, K concentration did not alter the number of new leaves, and shoot and root dry weights. Increasing K concentration did not affect the length but increased the width of the most recently fully expanded leaves (the sixth leaves). Plants under 0 K exhibited yellow spots and irregular chlorosis on old leaves being more severe at the middle of the blade and leaf tip. Numbers of leaves with yellow spots or chlorosis decreased with increasing K concentration. Chlorenchyma thickness was unaffected by K concentration, whereas water storage tissue and total leaf thickness increased with increasing K concentration. Leaf N concentration in the sixth or 10th leaf was unaffected by solution K concentration. However, plants at 0 mm K had higher N concentration in the 14th leaf than those in sixth and 10th leaves. Leaf P, Ca, and Mg concentrations decreased with increasing solution K concentration. K concentrations were higher in the sixth leaf than the 14th leaf in plants at 0, 2, or 4 mm K, whereas leaf K concentration was 15 g·kg−1 on dry weight basis in the sixth, 10th, or 14th leaves in plants treated with 6 mm K.
Chao-Yi Lin and Der-Ming Yeh
Hsin-Shan Lin and Chien Yi Wang
Off-season production of several tropical and subtropical fruits has been successfully practiced commercially in Taiwan. By combining pruning, removal of leaves, and application of growth regulators, it is possible to have two to three crops of grapes per year. By grafting the chilled scions of temperate Asian pear onto the water shoots of low-chilling native pear varieties, it is possible to produce high-quality Asian pears (temperate-origin) in a subtropical environment. By using techniques such as root-pruning, flooding, and application of growth inhibitors, it is possible to induce flower bud formation and hasten the production of wax apples. The production periods of other fruit crops such as jujubes and sugar apples, can also be modified by pruning and other techniques.
Yi-Lun Liao, Wen-Shin Lin and Shu-Yun Chen
San-Gwang Hwang, Yi-Ying Li and Huey-Ling Lin
The king oyster mushroom [Pleurotus eryngii (DC.:Fr.) Quél.] is gaining popularity across the world due to its excellent taste, high nutritional quality, medicinal value, and long shelf life. Conventional substrates for king oyster mushroom cultivation consist of sawdust derived from various tree species. Sawdust demand is increasing worldwide, creating a need for alternative materials that can at least partially replace sawdust as substrate for king oyster mushroom. In Taiwan, as in other countries that grow fruit trees, pruned fruit tree branches are an expensive agricultural waste, particularly if they are not recycled or reused. In the present study, we evaluated substrates containing sawdust and different proportions of material ground from pruned wax apple or Indian jujube branches for cultivation of king oyster mushroom. Our results suggested that among all five substrate mixes tested, the best substitute for conventional sawdust (100% sawdust) was a substrate that contained 75% sawdust mixed with 25% materials ground from trimmed wax apple branches (Wax apple 25%). Furthermore, determination of mineral element content, pH, and electrical conductivity (EC) levels of the substrates both before spawn inoculation and after harvesting revealed no significant changes in mineral content, a slight reduction in pH value, and a minor increase in EC levels after cultivation. Taken together, results from this study suggest that agricultural wastes from pruned fruit tree branches can partially replace sawdust as the cultivation substrate for king oyster mushroom.
Choun-Sea Lin, Huey-Ling Lin, Wann-Neng Jane, Han-Wen Hsiao, Chung-Chih Lin, Fang-Yi Jheng and Wei-Chin Chang
A xylem mutant (vse) was isolated from a Bambusa edulis (Odashima) Keng plantlet following vegetative micropropagation and subculture for 7 consecutive years and induced to proliferate in medium supplemented with 0.1 mg·L-1 (0.5 μm) thidiazuron (TDZ) and to develop roots in medium supplemented with 5 mg·L-1 (26.9 μm) α-naphthaleneacetic acid (NAA). Subsequent investigations comparing the growth habits of mutant plantlets with those of the wild type indicated that the growth of the former was retarded in a greenhouse. Several morphological abnormalities were observed in the vse mutant: it had thinner stems with fewer trichromes on the surface; the xylem vessels were smaller in diameter and contained crystal-like structures in the pith; the leaves were shorter and narrower with a sharp leaf blade angle; the roots were thinner and contained fewer xylem cells. The cation concentrations of both the mutant and wild type were similar in the in vitro analysis, except for those of iron and potassium, which were lower in mutant leaves in vivo. In 2-month-old mutant plants, iron chlorosis was observed on young leaves and a potassium deficiency was observed on older leaves. After 1 year of growth in the greenhouse, all of the wild-type plants had survived, but only 27% (16/60) of the mutant vse plants were alive.
Yi-Chen Chen, Wei-Chun Chang, San-Tai Wang and Shu-I Lin
Grafting is widely used in the commercial production of cucurbits (Cucurbitaceae) and solanaceous (Solanaceae) vegetables, but seldom in the production of cruciferous vegetables such as cabbage (Brassica oleracea Capitata group). In our study, we developed a tube grafting method for cabbage using the ‘K-Y cross’ cabbage as the scion and ‘Tsuei Jin’ chinese kale (B. oleracea Alboglabra group) as the rootstock (K-Y/TJ), and then used the K-Y/TJ grafted seedlings to identify the best healing conditions. The examined healing conditions included temperature (15, 20, or 25 °C), relative humidity (RH; 75%, 85%, or 95%), and light intensity (high light intensity, 79 to 107 μmol·m–2·s–1; low light intensity, 38.6 to 58.8 μmol·m–2·s–1; or full darkness, 0 μmol·m–2·s–1). Considering all the healing conditions, the K-Y/TJ grafted seedlings healing at 20 °C, 95% RH, and high light intensity exhibited survival rates of up to 96.7% and overall superior seedling quality. ‘K-Y cross’ cabbages were then grafted onto chinese kale rootstocks, and the head traits of all grafted plants were comparable to those of nongrafted and/or self-grafted ‘K-Y cross’ plants. ‘K-Y cross’ plants grafted on ‘Jie Lan’ chinese kale rootstocks had greater ascorbic acid and total soluble solid (TSS) contents than nongrafted and self-grafted ‘K-Y cross’ plants. Overall, this research describes a successful tube grafting method and the optimal healing conditions for grafted cabbage seedlings, which can be used as a tool to improve head quality.
Yi-Lu Jiang, Tzong-Shyan Lin, Ching-Lung Lee, Chung-Ruey Yen and Wen-Ju Yang
Yellow pitaya, Selenicereus megalanthus (Schum. ex. Vaupel) Moran, is a potential new fruit in Taiwan. It sprouts mostly in winter and flowers in late spring and fall. In this study, an average of 60% shoots within canopies flowered. Shoots sprouted in the current winter flowered in fall and produced winter fruits, and shoots sprouted earlier than the current winter flowered in late spring and produced summer fruits. Floral buds on most shoots appeared at the distal end. The weight, pulp percentage, and total soluble solids of winter fruits were significantly higher than those of summer fruits. The number of black seeds was positively correlated with pulp weight (R 2 = 0.87). The total soluble solids in the core region of winter fruits reached 22.7 °Brix, higher than that in other regions. Future efforts to improve yellow pitaya production in Taiwan include increasing winter fruit production by enhancing growth of the current year's new shoots through proper canopy management and increasing the size of summer fruit by artificial pollination, fruit thinning, and other means.
Yi-Lu Jiang, Yuan-Yin Liao, Meng-Tzu Lin and Wen-Ju Yang
Off-season flowering in red pitaya (Hylocereus sp.), a long-day plant, can be achieved using night-breaking (NB) treatment. Among the stages of bud development, stage 0 referred to induced but not yet differentiate any bracteole and stage 3 was the stage right before emerging floral buds and the bracteole differentiation was completed. Unlike floral bud emergence, bracteole differentiation was independent of the daylength and strongly influenced by the environmental temperature. The buds of higher stages were more effective in response to NB treatment and more sensitive to chilling injury (CI). Consequently, off-season flowers in autumn and winter trials were derived mainly from stage 2 and 3 buds and from stage 0 and 1 buds, respectively. In southern Taiwan, low night temperature between 10 Jan. and 7 Feb. 2011 may be the major factor, which delay bud development in off-season production. Therefore, we conducted a heating experiment in winter off-season production to proof our hypothesis and concluded that NB treatment should be applied along with night temperature elevation or after mid-February when the minimum night temperature is increasing.
Yi-Lu Jiang, Yuan-Yin Liao, Tzong-Shyan Lin, Ching-Lung Lee, Chung-Ruey Yen and Wen-Ju Yang
Red pitaya (Hylocereus sp.), which flowers between May and October and sprouts between November and May in Taiwan, has been confirmed to be a long-day plant. The areoles on the old shoots may be induced to flower after the March equinox naturally, and the floral bud formation occurs in two to three waves from May to October. We conducted experiments on photoperiodic regulation of floral bud formation from June to Dec. 2009 and tested the feasibility of off-season production in 2011. Shortening summer daylength to 8 h inhibited the areoles at the distal end of the shoots to develop into floral buds and promoted sprouting at the proximal ends of the shoots. Night-breaking treatment between the September equinox and the winter solstice led to floral bud formation. The critical daylength seemed to be ≈12 h, and night-breaking treatment would be applicable between the September and the next March equinoxes to produce off-season crops. The duration of night-breaking required for flower differentiation was longer in the cooler than in the warmer season. Four weeks of night-breaking treatment was sufficient to promote flowering in late fall (mid-October to mid-November), but 3 months were required to generate similar result in the winter and early spring (January to March) in southern Taiwan.
Jehanzeb Khan, Yubin Yang, Qiang Fu, Weiqiang Shao, Jianke Wang, Li Shen, Yan Huai, Guy Kateta Malangisha, Abid Ali, Ahmed Mahmoud, Yi Lin, Yongyuan Ren, Jinghua Yang, Zhongyuan Hu and Mingfang Zhang
Watermelon (Citrullus lanatus) is an important horticultural crop that is sensitive to heavy metals such as lead (Pb) in polluted water or soil. However, there are no available data regarding Pb tolerance phenotyping in watermelon. Watermelon seedlings were exposed to various Pb doses (0, 20, 40, 60, 80 µm·L–1 Pb) for 14 days, after which 20 µm Pb was identified as the optimal treatment for lead tolerance analysis in watermelon because it caused significant symptoms (leaf chlorosis, stubby and yellow roots) but little damage to seedlings. Subsequently, the Pb responses were analyzed in eight watermelon varieties (V1–V8), and membership function analysis was used to determine a single Pb tolerance index. Of the eight watermelon varieties, V4 and V7 were ranked the most Pb tolerant; V1, V2, V5, and V6 were moderately Pb tolerant; and V3 and V8 were the most Pb-sensitive varieties. Compared with most Pb-sensitive varieties (V3 and V8), the most Pb-tolerant varieties (V4 and V7) maintained high antioxidant activity, and had lower malondialdehyde (MDA) and total soluble protein (TSP) contents. In addition, carotenoid and chlorophyll (both a and b) contents were stimulated and inhibited, respectively, in leaves of high-Pb translocation varieties (V4 and V8). Principal component analysis (PCA) revealed relative root length as an indicator of Pb tolerance because it correlated significantly with shoot growth. These results provide useful insight into the mechanism of Pb tolerance in cucurbit crops, as well as information regarding the breeding of watermelon with enhanced tolerance to this heavy metal (Pb).