Chin-Mu Chen and Der-Ming Yeh
Xuejuan Chen, Ming Sun, Jianguo Liang, Hui Xue and Qixiang Zhang
Chrysanthemums have beautiful flowers with high ornamental value and rich genetic diversity. Amplified fragment length polymorphism (AFLP) markers were used to detect the relationships among 12 wild accessions and 62 groundcover chrysanthemum cultivars. Nineteen EcoRI/MseI primer combinations revealed 452 informative polymorphic bands with a mean of 23.8 bands and 71.5% polymorphic rate per primer pair. Jaccard’s coefficient of similarity varied from 0.64 to 0.89, indicating much genetic variation in chrysanthemums. The 74 accessions were classified into two major groups by unweighted pair group method with the arithmetic averages (UPGMA). The dendrogram showed that AFLP variability was closely correlated with both geographic distribution and traditional classification of the wild accessions. Among all accessions, genetic relationship was the most relevant factor in AFLP-marker clustering, whereas petal type was also informative. AFLP technology could be very efficient for discriminating species of chrysanthemum and its related genera and reconstruct their genetic relatedness.
Chin-Mu Chen, Tzu-Yao Wei and Der-Ming Yeh
A double-flowered periwinkle [Catharanthus roseus (L.) G. Don.] mutant TYV1 was identified and the morphology and inheritance of the double-flowered phenotype was studied. TYV1 has an outer salverform whorl of petals and an additional inner funnel-shaped whorl of petals originating from the apex of the corolla. The apex of corolla tube forms a narrow opening. There are hairs under the opening at the apex. The stigma in this mutant is set below the anthers. The overlap between the top end of the pistil and bottom ends of anthers in TYV1 flowers at 1 to 2 days after anthesis is 0.56 ± 0.01 mm. TYV1 could be used as either the male or female parent in crossing. Self-pollinated TYV1 produced all double-flowered progeny compared with self-pollinated single-flowered cultivars Little Pinkie and Titan Burgundy, which produced all single-flowered progeny. F1 plants between TYV1 and ‘Little Pinkie’ or ‘Titan Burgundy’ were all single. Three F2 populations segregated into 3 single: 1 double ratio. Backcrossing F1 to seed parents also indicated that a double-flowered form was controlled by a recessive allele. A single dominant gene expressed in the homozygous or heterozygous state resulted in the single-flowered phenotype. All the young seedlings of self-pollinated TYV1 and double-flowered progeny had distorted leaves before the sixth pair of leaves emerged.
Junne-Jih Chen, Ming-Chung Liu and Yang-Hsiu Ho
Tuber production of calla lily (Zantedeschia elliottiana Spreng cv. Super Gold) was investigated using three size ranges (7-10, 4-7, and <4 mm shoot diameter) of in vitro plantlets acclimated in either pots or soil beds in a protected house. The shoots and tubers of large plantlets exhibited higher rates of dry-matter accumulation than did those of small plantlets. The diameter of tubers harvested from pots ranged from 0.67 to 4.1 cm with median values of 2.7, 2.1, and 1.9 cm for the plants derived from large, medium, and small plantlets, respectively. Plants grown in soil beds, regardless of size, produced larger tubers than did those grown in pots. Tubers >3 cm in diameter developed on 25% and 52% of plants grown in pots and soil beds, respectively. Our results suggest that improved calla lily production could be realized by using larger in vitro plantlets as the source material and growing them in soil beds in a protected house.
Jee-Song Chen, Fang-Ming Thseng and W.H. Ko
Stock plants of tea [Camellia sinensis (L.) Kuntze cv. Chin-shin Oolong] were sprayed three times at weekly intervals with benomyl before taking cuttings. The survival rate of cuttings was increased from 3.3% in the nontreated controls to 76% in 1986 and from 6.4% to 83% in 1987. The treatment also greatly improved the subsequent growth of cuttings. Soaking cuttings in benomyl solution before sticking slightly improved survival and subsequent growth of cuttings. Chemical name used: methyl[1-[(butylamino)carbonyl]-1H-benzimidazol-2-yl]carbamate (benomyl).
Hui-Mei Chen, Hung-Ming Tu and Chaang-Iuan Ho
The main purpose of this research was to explore individuals' attitudes toward horticultural activities. The research was conducted in two stages. First, open-ended interviews were used to conceptualize attitudes toward horticultural activities, and seven themes and several subthemes of attitudes were induced. Based on the results, a questionnaire was then designed and a quantitative survey was conducted to identify the dimensions of attitudes toward horticultural activities and their interrelationships. Five dimensions of attitudes toward horticultural activities were extracted: increasing positive mood, improving the environment, leisure belief, improving social relationships, and escaping. These dimensions of attitudes toward horticultural activities had activity-based attributes that differed to some extent from those of general leisure. The dimension of improving the environment was particularly salient for horticultural activities. Propositions and recommendations to stimulate future research about developing a valid measurement instrument are offered.
Chang-Tsern Chen, Ching-Lung Lee and Der-Ming Yeh
Growth and photosynthetic parameters were measured in Eustoma grandiflorum (Raf.) Shinn. ‘Umihonoka’ grown hydroponically under nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), or magnesium (Mg) deficiency in 1/2 strength of modified Johnson’s solution. Plant height, node number, and leaf area were all reduced under N, P, K, and Ca deficiencies but not under Mg deficiency as compared with plants grown in the complete nutrient solution. Shoot and root dry weight were reduced in the N-, P-, K-, and Ca-deficient treatments, whereas root but not shoot dry weight was lowered by Mg-deficient treatment. Shoot-to-root dry weight ratio decreased under N and P deficiencies, increased under K and Mg deficiency, but was not altered under Ca deficiency. Decreased net photosynthetic rate (Pn) of N-, P-, and K-deficient leaves was all related to lower stomatal conductance (g S), whereas N-deficient leaves also accompanied by a higher intercellular carbon dioxide concentration (Ci). The Mg-deficient treatment did not alter chlorophyll fluorescence Fv/Fm, maximal fluorescence (Fm), or minimal fluorescence (Fo). Decreased Fv/Fm of N-, P-, K-, and Ca-deficient leaves was all related to lower Fm, whereas N- and P-deficient leaves also accompanied by lower Fo. A key was developed for the identification of N, P, K, Ca, and Mg deficiency symptoms.
Ying Chen, Xinlu Chen, Fei Hu, Hua Yang, Li Yue, Robert N. Trigiano and Zong-Ming (Max) Cheng
Agave species are economically important plants in tropical and subtropical desert ecosystems as ornamentals as well as potential bioenergy crops. However, their relatively long life cycles and the current lack of biotechnology tools hinder their breeding. In this study, an efficient system for micropropagation was developed for Agave americana L. by using basal stems as explants and grown on a modified Murashige and Skoog medium (MSI) or a 1/2 MSI medium supplemented with various concentrations of 6-benzylaminopurine (BA) for shoot proliferation. The highest number of shoots (18.5 shoots/explant) from basal stems was obtained on MSI supplemented with 13.32 μM BA. An efficient shoot regeneration system was also developed from leaf tissues. Combinations of auxin with cytokinin, basal media, and leaf regions were optimized for shoot induction. Adventitious shoot formation from leaf segments was induced and proliferated with combination ranging of 0.54 to 2.68 μM [α-naphthaleneacetic acid (NAA)] with 8.88 to 13.32 μM (BA), and the maximum frequency (≈69%) was obtained with 2.68 μM NAA plus 13.32 μM BA. MSI medium and the basal segment of leaf affected shoot induction. The highest rooting frequency and mean number of shoots occurred in 1/2 MSI containing with 4.92 μM indole-3-butyric acid (IBA) alone (90%, 3.4) or 1.48 μM IBA plus 1.61 μM NAA (92%, 5.2). Survival of in vitro plantlets after transfer and acclimatization to ex vitro conditions was 87%. This is the first complete protocol for micropropagation of A. americana.
Xinjing Qu, Hui Wang, Ming Chen, Jiao Liao, Jun Yuan and Genhua Niu
Oil tea (Camellia oleifera) is an important edible oil tree. However, its growth and yield are strongly limited by drought. This study investigated the physiological and metabolic responses of two common oil tea cultivars, Huajin and Changlin53, to moderate and severe drought stress. Based on the photosynthetic and physiological indices, ‘Changlin53’ may be more tolerant to drought than ‘Huajin’. A total of 41 key metabolites induced by drought stress, including 12 amino acids, 12 organic acids, 10 carbohydrates, 3 fatty acids, and 4 phenols, have been identified by liquid chromatography-mass spectrometry. Under moderate drought stress, the contents of carbohydrates, amino acids, and some organic acids in ‘Changlin53’ were significantly increased; however, under severe drought stress, the contents of soluble sugars were decreased and the synthesis ability of amino acids and organic acids were enhanced. The glutamic acid–mediated proline biosynthesis pathway and salicylic acid synthesis were continuously upregulated in ‘Changlin53’ under moderate and severe drought stress, which could regulate osmotic pressure and maintain intracellular environmental stability. Under moderate drought stress, the contents of monosaccharides, amino acids, and organic acids increased in ‘Huajin’ leaves. Furthermore, the shikimic acid–mediated secondary metabolite synthesis pathway was weakened. More secondary metabolites were used to increase glycolysis and tricarboxylic acid cycle to accelerate energy production and to enhance the glutamic acid–mediated proline biosynthesis pathway, which are necessary to increase osmotic regulation. Under severe drought stress, the contents of carbohydrates, organic acids, and some amino acids were significantly decreased in ‘Huajin’ leaves, indicating serious damage. These results deepened our understanding of the mechanisms involved in oil tea drought tolerance, which will help improve water management of oil tea seedlings.
Huan-Keng Lin, Tzu-Yao Wei, Chin-Mu Chen and Der-Ming Yeh
Stem anatomy and modulus of elasticity (MOE) were compared between upright and trailing cultivars of periwinkle [Catharanthus roseus (G.) Don.]. The inheritance of growth habit and flower form was also studied. Internode cross sections revealed that phloem fiber was distributed at the inner cortex in upright cultivars but not in trailing cultivars. Except the youngest internode, the upright ‘Vitesse Pink’ had the highest MOE throughout the 1st–13th internodes above the cotyledon. The more trailing ‘Cora Cascade Strawberry’ had consistently lower MOE than a less trailing ‘Cora Cascade Polka Dot’. All F1 plants between upright and trailing cultivars were upright, and the F2 generation derived from self-pollinating F1 fit a 3 upright : 1 trailing segregation ratio. All F1 plants between upright/double-flower and trailing/single-flower exhibited upright and single-flowers, whereas plants in the F2 generation fitted a 9 upright/single-flower : 3 trailing/single-flower : 3 upright/double-flower : 1 trailing/double-flower ratio. New double-flowered periwinkle selections with trailing growth habit were successfully developed from the F2 population.