Pollination Methods and Embryo Rescue Techniques of Hybridization between Lilium Oriental Hybrids

The pollination methods and embryo rescue techniques of hybridization between I.ilium Oriental hybrids were studied in this paper. The results showed that ： （ 1 ） in the combination of ＇ Justina＇ x ＇ Shala＇, pollen tubes were observed to grow downward in styles and target to ovules in ovaries when normal sti^na 13o1- lination method was used; pollen tubes were found to grow directionless to a different degree at stylar cuts and in ovaries when cut-style pollination method was used; the longer the styles were left, the more pollen tubes toward to ovules were observed and more plump seeds were produced; the maximum plump seeds were obtained via normal stigma pollination. （2） Hybridization experiments were performed for the 56 combinations of Lilium Oriental hybrids with normal stigma pollina- tion, and one combination generated no plump ovule and three combinations generated fewer than 10 plump ovules while the other 52 combinations generated plenty of plump ovules, which preliminarily indicated that normal stigma pollination method could be used as an universal pollination technique for hybridization between Lilium Oriental hybrids. The experiment results of different embryo rescue techniques showed that using cut-ovule inoculation about 70 d after pollination had a fas- ter germination speed and a higher germination rate of hybrid embryo than normal ovule inoculation, and embryo rescue efficiency of the former method was obviously higher than ＂embryo isolated inoculation＂ on 40 d after pollination. The research suggested that ＂cut-ovule inoculation＂ about 70 d after pollination could be regarded as an universal embryo rescue technique for hybridization between Lilium Oriental hybrids.

Photosynthetic characteristics of three varieties of Lilium “Oriental Hybrids”in the central areas of Yunnan Province, China

To understand the ecophysiological adapta-tion of Lilium"Oriental Hybrids",which are grown for their commercial bulbs,the gas exchange,leaf N and chlorophyll content of the three varieties were investigated in the central areas of the Yunnan Province.Among the three varieties,light-saturated photosynthetic rate at ambient CO_(2)(Amax)of Tiber was the highest,while that of Siberia was the lowest.The difference in the Amax was related to the carboxylation efficiency(CE),leaf mass per unit area and leaf N content per mass,which indicated that their photosynthetic capacity was influenced by the activity and/or the quantity of Rubisco.The three vari-eties had lower photosynthetic saturation points and pho-tosynthetic compensation points,but the photosynthetic rates were not decreased up to 2000 μmol·m^(-2)·s^(-1) of the light intensity.This indicates that the three varieties had broad adaptability to light intensity.There were signifi-cant differences in the photosyn thetic optimum temper-ature among the three varieties.Siberia had the highest photosynthetic optimum temperature(25.5℃-34.9℃),and is likely to grow well in warm areas.Sorbonne had the lowest photosynthetic optimum temperature(19.3℃-25.6℃),and its growth is favored in cool areas.Tiber can maintain a high photosynthetic rate within a wide range of temperature.Therefore,Tiber is the most suitable variety for the climate in the central areas of the Yunn an Province,China.

The Dynamics of Changes in Starch and Lipid Droplets and Sub-Cellular Localization of β-Amylase During the Growth of Lily Bulbs

The ultra-structure of mother and outer daughter scales of Lilium Oriental hybrid Sorbonne were studied using transmission electron microscope to examine the sub-cellular localization of starch and lipid droplets during growth and development from shoot emergence to senescence.The contents of starch granules and lipid droplets in the cell of the mother scales decreased significantly from shoot emergence to anthesis,indicating that these scales served as a source for growth and development.After flowering,the number of starch granules and lipid droplets increased dramatically,and finally the cells were filled with the above molecules indicating that the bulb becomes a major sink during bulb enlargement.Ultrastructure observation also showed that symplastic pathway is the main pathway in cells in the exchange and transportation of material during bulb development.The activity of β-amylase,one of the key enzymes catalyzing starch breakdown,showed a similar trend.The enzyme sub-cellular localization via immune-gold electron-microscopy showed that βamylase was predominantly located together with starch granules,while the gold particles were scarcely found in other sub-cellular compartments.The result suggested that this enzyme is compartmented together with its functional substrate supporting its function in catalyzing starch breakdown in living plant cells.