[Study on exogenous hormones inducing parthenocarpy fruit growth and development and quality of Siraitia grosvenorii].

To explore the growth and development and analyze the quality of the parthenocarpy fruit induced by exogenous hormones of Siraitia grosvenorii. the horizontal and vertical diameter, volume of the fruit were respectively measured by morphological and the content of endogenous hormones were determined by ELISA. The size and seed and content of mogrosides of mature fruit were determined. The results showed that the fruit of parthenocarpy was seedless and its growth and development is similar to the diploid fruit by hand pollination and triploid fruit by hand pollination or hormones. But the absolute value of horizontal and vertical diameter, volume of parthenocarpy fruit was less than those of fruit by hand pollination, while triploid was opposite. The content of IAA, ABA and ratio of ABA/GA was obviously wavy. At 0-30 d the content of IAA and ABA of parthenocarpy fruit first reduced then increased, content of IAA and GA parthenocarpy fruit was higher than that of fruit by hand pollination. Mogrosides of parthenocarpy fruit was close to pollination fruit. Hormones can induce S. grosvenorii parthenocarpy to get seedless fruit and the fruit shape and size and quality is close to normal diploid fruit by hand pollination and better than triploid fruit by hormone or hand pollination.

[Rapid propagation system for tissure culture of Smilax glabra].

OBJECTIVE: Establishing the rapid propagation for plant tissue culture of Smilax glabra in order to rationally protect and utilize the resource. METHODS: The seed, shoot, leaf and rhizome of Similax glabra were cultured as explants. Different media and plant growth regulators at different concerntration were used. RESULTS: The best medium for bud induction was MS + 6-BA 2.0 mg/L + NAA 0.05 mg/L; The optimal medium for proliferation culture was MS +6-BA 2.0 mg/L + NAA 0.5 mg/L; The optimal medium for rooting was H + IBA 0.5 mg/L + NAA 0.5 mg/L; The optimal stroma for seedlings was 50% peat + 50% river sand. CONCLUSION: Different explants except leaf can be induced for tissue culture and rhizome has the optimal bud induction rate. An effective approach for rapid propagation has been provided,which can promote the artificial cultivation of Smilax glabra.

[Extraction of total RNA and cloning of sgDHAR gene from Siraitia grosvenorii].

Total RNA was isolated from Siraitia grosvenorii fruit by the method of modified Trizol, according to S. grosvenorii fruit characteristics of rich phenols, polysaccharide, oil and proteins. The OD260/280, OD260/230, RNA integrity (RIN) and yield of the total RNA with this method were 2.01, 2.02, 9.50 and 260 mirog.g-1, respectively. The open reading frame (ORF) of dehydroascorbate reductase (DHAR), named as SgDHAR, was cloned by rapid amplification of cDNA ends (RACE) and RT-PCR method from S. grosvenorii. The GenBank accession number for this gene is KC907731. The SgDHAR gene contains a full-length cDNA of 1,252 bp including ORF of 819 bp and encodes a predicted protein of 272 amino acids. The molecular mass is 30.217 7 kD and the isoelectric point is 8.76. Homology comparison showed that it shared 87% nucleotide sequence homology with Cucumis sativus. Expression patterns using qRT-PCR analysis showed that SgDHAR was mainly expressed in fruit and stem, followed by flower, and was lowest in root, while the expression level was 6.83 times in triploid. T than that in diploid. Therefore, SgDHAR gene may be involved in abortion of triploid seedless S. grosvenorii.

[Effect of Nutrient Solution in Soilless Cultivation on Growth, Antioxidase Activities and Amino Acid Contents of Nervilia fordii].

OBJECTIVE: To select the best formula for soilless cultivation of Nervilia fordii. METHODS: Four different formulas of nutrient solution on growth,antioxidase activities and amino acid contents were investigated. RESULTS: The concentration of 1/2 lettuce nutrient solution formula was the most propitious for the growth of Nervilia fordii, the antioxidase activities and amino acid contents were increased in the treatment of nutrient solution,and the highest amino acid content was observed in 1/2 dose of green leafy vegetables nutrient solution formula. CONCLUSION: The concentration of 1/2 lettuce nutrient solution formula is the optimal solution for growth of Nervilia fordii, the results of this study provides academic and technological basis for soilless cultivation of Nervilia fordii.

[Study on quantitative assessment of Siraitia grosvenorii germplasms by general index].

OBJECTIVE: To establish a weight-marking method and evaluate Siraitia grosvenorii germplasms. METHOD: The characters of 21 kinds of S. grosvenorii germplasms in the field and the lab were analyzed, seven important characters were selected to weight the marks. A general evaluation index was made and used to evaluate S. grosvenorii germplasms. RESULT: The evaluation result of 21 kinds of S. grosvenorii germplasms by the weight-marking method was consistent with production practice. Meanwhile, the new variety Yongqing No. 1 and major cultivars were the superior germplasms. CONCLUSION: A rational technique system of evaluating S. grosvenorii germplasms was established, and the superior germplasms were selected.

[Progress on research of tissue culture of Siraitia grosvenorii].

In this paper we reviewed the development of tissue culture, current situations of virus-free plantlets industrialization and the way to deal with the situations, application prospects of Siraitia grosvenorii so as to give some advice for its further study and application.