| Malus sieversii, a precious tertiary relict in the world, is the second important protected plant in the endangered rare germplasm resources in China. It mainly spread over Central Asia and Xinjiang in China. Malus sieversii has been listed as a national priority protected species of international importance of biodiversity. The research on Malus sieversii reveals the origin of mountain broad-leaved forest in central desert region of Asian and provide evidence of plant migration. In recent years, the distribution and population of Malus sieversii decrease day by day and the species on undergoes the progress of extinction due to interference of human activities and pests attack. It is very urgent to protect the Malus sieversii resource. The investigation on resources distribution and biological diversity of seed and fruit, optimization of tissue culture conditions, and SPL3 expression changes involved in growth regulation in Malus sieversii play an important role in understanding of Malus sieversii biological characteristics, tissue culture conditions and growth and development of specific laws. 1 Malus sieversii resources field surveyThe survey was conducted Malus sieversii flowering(April), survey population is Xinyuan, Nalati population. Through the survey found, under normal weather conditions, Malus sieversii flowering is in April each year. The mainly mode of reproduction update of Malus sieversii is seed propagation and root sucker breeding. Malus sieversii is suffering from a serious pest and disease problems. 2 Malus sieversii seed biological characteristics studyBy studying seed biological indicators, seed moisture content, seed imbibition characteristics, the result showed that among different populations Malus sieversii seed shape trait diversity. The maximum longitudinal diameter of Da Xi Gou population is 8.10 mm, the maximum diameter is 4.30 mm; the maximum seed aspect ratio is 2.19, high seed plumpness, seed color mostly are brown. The maximum longitudinal diameter of Nalati population is 7.26 mm, the maximum diameter is 3.53 mm; the maximum seed aspect ratio is 2.14, seed size have big difference, poor seed plumpness seed color are light brown, dark brown. Seed moisture content was no significant difference in the same population, the seed moisture content of Gong Liu population collected in 2013 between 5.97 %- 4.78 %; the seed moisture content of Nalati population collected in 2013 between 5.57-4.55%; the seed moisture content of Xinyuan population collected in 2013 between 5.35-5.00%. The seed moisture content of Da Xi Gou population collected in 2014 between 6.00-5.75%; the seed moisture content of Nalati population collected in 2014 between 6.53-6.10%. The seed water absorption, seed water absorption in TKW seeds are differences between different populations, seed moisture absorption rate and water use efficiency is not very different. 3 Comparison of vitamin C and soluble protein content of Malus sieversii fruitsBy the spectrophotometric method and coomassie brilliant blue method to measurement and comparison the content of vitamin C and soluble protein, the results showed that vitamin C in fresh fruits of Daxigou area was extremely significant different, the soluble protein in fresh fruits was not significant difference. Vitamin C and soluble protein in fresh fruits of Xinyuan area were significant difference. The vitamin C and soluble protein in fresh fruits of Nalati and Xinyuan-Gongliu area were not significant difference. Different in difference population were significant. The content of vitamin C and soluble protein in fresh fruits of Nalati area was the highest. The Vc content was 5.36 mg/100 g, and the soluble protein content was 0.491 %. 4 Malus sieversii tissue culture studyBy the tissue culture conduct Malus sieversii vitro culture propagation study, the results showed that the favorable explant induced cultures medium formula was modified MS+6-BA 2.00 mg/L+NAA 0.05mg/L, the favorable disinfection is CH3CH2 OH 70% for 30 s +Hg Cl2 0.1% for 8min+sterile water 5 times, the favorable sampling time is April. The favorable subculture induced cultures medium formula was modified MS+6-BA 3.00 mg/L. the favorable callus induced from the leaf medium formula was modified MS+TDZ 3.00 mg/L+NAA 0.5 mg/L, the favorable cutting place of callus induced from the leaf is cutting the primary vein crosswise, the favorable dark period of callus induced from the leaf is 20 d.5 The expression of mi R156 target SPL3 in Malus sieversiiBy real-time quantitative RT-PCR method to analyzing the expression of mi R156 target SPL3 in different tree-ages Malus sieversii, the result showed with the growth of tree-age a increase in the expression of SPL3, Low expression in juvenile phase and high expression in adult phase. It prove the signal path of mi R156/ SPL3, affected by other factors in age from different materials in aseptic tissue culture, and the factors close contact with age. |
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