| Rhododendron moulmainense Hook f.,the shrubs or small trees of the genus of Rhododendron,the family of Ericaceae,distribute wildly and largely in Shenzhen Wutong Mountain at 600-800 m elevations.In the blooming season,the scenery is spectacular and rare landscape in Shenzhen city.Reproductive biology,its adaptability after vertical introduction and the tissue culture regeneration system of R.moulmainense were researched in this paper,which would provide the foundation for the development,utilization and promotion of R.moulmainense..(1)Reproductive biology:The floral phenological period and traits,floral dynamic,pollen viability,stigma receptivity,flower-visiting insects,and breeding system of R.moulmainense were investigated and studied.The results showed that R.moulmainense flowered from the inid-to-late of March to April.The inflorescence of R.moulmainense was apical umbel,which was composed of 5-8 florets that opens symmetrically from the outside to inside in the night 10:00 to morning 4:00.The best stigma receptivity was 24h after anthesis and the best pollen vigour was the first day at anthesis.Bees were the main effective pollinators of R.moulmainense,which were active in 8:00 am-9:30 am,11:30 am-12:30 am,15:00 pm-16:00 pm.The breeding system was outcrossing with self-incompatibility and xenogamy was the dominant pollinated method.(2)The adaptability after vertical introduction:In low-lying areas,the split-plot experuent design was adopted,different shading(0%,20%,50%,80%)was the main plot and different soil water drainage(high bed and flat bed)was the subplot,the plant increment and some physiological indexes in leaves of R.moulmainense were researched,and assessment of adaptability and the correlation among different indexes were also analyzed.The results showed that under 50%shading and high bed.the branch increment.RWC(relative water content),Chlt(total Chlorophyll content),Pmx(maximum net photosynthetic rate).AQY(apparent quantum yield),daily average Pn(net photosynthetic rate),daily average WUE(water use efficiency),daily average Pn/PAR(photosyntheticcally active radiation),root respiration rate,MDH activities in leaf of R.moulmainense were higher or the highest,and relative conductivity,content of MDA,soluble sugar and soluble protein,SOD activities,POD activities were lower or the lowest.Chl a/Chl b(Chlorophyll a/Chlorophyll b),LCP(light compensation point).I.SP(light saturation point),Rd(dark respiration rate),LDH activities,PDC activities,ADH activities were lower or the lowest.In general,with enhancing of shading and soil water drainage,the branch increment.Chlorophyll content.RWC,Chl t,Pmax,AQY.daily average Pn,daily average WUE,daily average Pn/PAR,root respiration rate in leaf appear the trend of increasing gradually,while other indexes all appeared the trend of decreasing gradually.The correlation analysis result showed that there was extremely significant correlation between light intension and RWC,Chl a,Chl b,Chl t,Chl a/Chl b,LSP,LCP,Pn/PAR,and between soil water content and root respiration rate,Pn.It was concluded through principal component analysis that the scores of R.moulmainense with 50%shading and high bed was the highest.(3)Tissue culture:The tissue culture rapid propagate system was researched by disinfection of explant,proliferation culture,bud elongation culture,rooting and transplanting of seedling with the explants of immature stems of R.moulmainense.The results showed that the best explant sterilization methods was that 70%alcohol for 10s,2%NaCIO for 15 min,washed with distilled water for 5-6 times.Adventitious bud proliferation culture media was WPM+ZT 2.0 mg/L+NAA0.5 mg/L+ 30 g/L sucrose,pH=5.0,and WPM+TDZ 0.1 mg/L+NAA 0.5 mg/L+30 g/L sucrose.pH=5.0 with bud elongation culture medium WPM+ZT0.5 mg/L+GA3 2.0mg/L+30g/L sucrose,pH=5.0.The rooting medium was WPM+IAA 0.1 mg/L+1%sucrose,pH=5.0.The transplanting matrix was perlite:peat soil 1:1 with more than 90%transplanting survival rates. |
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