The results in Table 6 show that the highest theoretical yield of vegetables was obtained the maximum value at T2, which is not significantly different from T3 and T5, but significantly higher (P < 0.01) than T1 and T4. The actual harvested yield had the highest value in T3 (1362.5 kg/1000 m2), not significantly different from T2 (1327.3 kg/1000 m2) and T5 (1231.4 kg/1000 m2). However, the difference was significant higher (P < 0.05) than T1 (741.6 kg/1000 m2) and T4 (850.8 kg/1000 m2) (Table 6).
Zaman, M., Ahmed, M. J., & Gogoi, P. (2009). Effect of Bokashi on plant growth, yield and essential oil quantity and quality in Patchouli (Pogostemon cablin Benth.).
Biosciences, Biotechnology Research Asia 7(1), 383-387.
SELECTION OF NON-FLOWER FADING Dahlia variabilis ‘NESSHO’ PLANTS BASED ON FLAVONE SYNTHASE GENE (DvFNS) EXPRESSION PATTERNS Edna K. Muthamia*, Misaki Ando, Ken-ichiro Yasuba, Yuichi Yoshida, Tanjuro Goto
and Yoshikuni Kitamura
Department of Crop Science, Division of Agriculture and Life Science, Graduate school of Environmental and Life Science Okayama University, Okayama city, Japan.
*Email: [email protected] Abstract
Dahlia variabilis ‘Nessho’ cultivar exhibits flower fading characteristics from autumn to spring. The color changing phenomenon is attributed to Dahlia variabilis flavone synthase gene (DvFNS) expression in whole plant level. Our previous studies suggested that the DvFNS expression in young leaves under the appropriate environmental conditions correlates with the potential for fading occurrence in flowers. In this study, we verified the potential for application of DvFNS expression analysis in young leaves for the selection of plants that rarely exhibit flower fading. Plants that had earlier been screened and classified as candidates highly sensitive to flower fading (CRH) and low sensitive (CRL) plants were used. The plants were first maintained under acclimation conditions (day temperature at 25℃ from 06:00 to 18:00 o’clock and night temperature at 20℃ from 18:00 to 06:00 o’clock) for 2 weeks to eliminate the effect of greenhouse conditions on the DvFNS expression. The plants were then maintaining under DvFNS inductive conditions (day temperatures at 20°C from 08:00-18:00 o’clock and night temperatures at 9℃ 18:00-08:00 o’clock) for 2 weeks. Young unexpanded leaves were sampled and relative DvFNS expression analyzed by real time qPCR. There was significant elevation in expression of DvFNS gene in CRH plants with up to 2.5 times increase before and after inductive treatment. On the contrary, there was no significant change in CRL plants. The findings provide a faster and alternative way for selection of plantlets that will produce red flower color without flower color confirmation.
Keywords: Dahlia, DvFNS, flower fading, plantlet selection Introduction
Flower color is one of the most important quality traits in ornamental plants as it determines the commercial value of a flower. The color of the ray florets results from the accumulation of secondary metabolites such as flavonoids including anthocyanins and flavones. Deep color intensities result from higher pigment accumulation whereas pale colors result from lower pigment accumulation (Tanaka et al., 2008). White and yellow coloration in flowers is as a result of incomplete anthocyanin biosynthesis process. The red color is as a result of accumulation of anthocyanins (Halbwirth et al., 2008).
Dahlia (Dahlia variabilis) belongs to the family Asteraceae and the flowers vary in shape, size and color because of its polyploidy nature (Gatt et al., 1998). The variation in flower color ranges from red, yellow, purple, pink, ivory, and black (McClaren, 2009). The pigments that accumulate in the ray florets are mainly anthocyanins, flavones, buteins, and their derivatives (Yamaguchi et al., 1999) hence floral color is based on the final pigment product of the anthocyanin biosynthetic pathway.
D. variabilis `Nessho` cultivar is popular because of its solid red flower color. However, the cultivar has a unique characteristic where it exhibits flower fading during winter and spring even in plants that produce solid red flowers during summer and autumn. In a study comparing dahlia `Kokucho` a black cultivar and its purple mutant showed that suppression of Dahlia variabilis flavone synthase gene (DvFNS) abolishes the competition in the synthesis of
anthocyanidin and flavone leading to higher accumulation of anthocyanins (Deguchi et al., 2013). In `Nessho` the flower color is also affected by the expression level of DvFNS in the whole plant (Okada et al., 2018). High temperature in autumn and summer suppresses DvFNS expression favoring high anthocyanin accumulation hence the production of solid red color flowers. Low temperature in winter and spring induces DvFNS expression hence higher flavones synthesis and accumulation leading to faded flowers. Nevertheless, there are plant strains that can produce flowers with stable color throughout the seasons. Such strains are desirable for good quality `Nessho` flower production in Japan throughout the year. The stable plant strains can be propagated asexually through cuttings for consistent quality production.
Selection for non-fading strains, however, takes a long time because plants have to be selected for solid red flower color production during winter and spring seasons. A faster selection method is therefore desirable.
In dahlia `Nessho` cultivar, there is also a correlation between DvFNS gene expression levels in young unexpanded leaves and flower color expression (Okada et al., 2018). In the current study, we sort to validate this correlation to use it as a selection method for non-fading strains.
We compared DvFNS gene expression in young unexpanded leaves of relatively low sensitive and relatively high sensitive plants before and after DvFNS gene inductive conditions treatment.
2. Materials and Methods