| It is an important direction of ecological restoration research that using hyperaccumulators and tolerance plants to remediate heavy metals contaminated soil. There is a variety of species in Sedum sensu lato and Silene, including hyperaccumulators. Moreover, genus Silene has dioecious, male sterility, and other special types of the breeding system. It is an excellent material to cross-breeding and study male sterility.Through a pot experiment under 0,25,50,100,200 and 400 mg·kg-1 Cd concentrations, this paper studied heavy metal accumulation and tolerance characteristics of 11 species in Sedum sensu lato.There species were Phedimus spurius’Coccinea’, Phedimus kamtschaticus, Phedimus aizoon, Sedum sarmentosum, Sedum lineare, Sedum rupestre, Sedum sexangulare, Sedum acre’Oktoberfest’, Sedum alfredii, Sedum album’Coral Carpet’, Hylotelephium erythrostictum. Sedum rupestre, S. sarmentosum, Phedimus kamtschaticus and S. sexangulare have showed strong tolerance to Cd. Because their shoot dry weight were not significantly different under all treatment. Otherwise, their tolerance indexes were all above 0.5 and the death rates were all very low. There were 6 and 9 species Cd accumulation in shoot above 100mg·kg-1 under 200mg·kg-1 and 400mg·kg-1 Cd treatment respectively. Phedimus spurius ’Coccinea’ contented 749.72 mg·kg-1 Cd in shoot under 400mg·kg-1 Cd treatment,which was the largest among all species under all treatment. Bioaccumulation and translocation factor of shoot reached maximum under 0 mg·kg-1 Cd treatment. Phedimus aizoon had the largest shoot bioaccumulation and translocation factor, which value are 13.51 and 9.19 respectively. Cluster analysis showed that S. rupestre, P. kamtschaticus, S. sarmentosum, S.sexangulare had strong tolerance to cadmium, but low accumulation aboveground; P.spurious’Coccinea’had relatively strong tolerance to cadmium, and the hightest accumulation in shoot; S. lineare, S. alfredii, S. acre’Oktoberfest’, S.album’Coral Carpet’showed poor tolerance to cadmium, but a relatively high amount of accumulation in shoot; H. erythrostictum, P. aizoon also had poor tolerance to cadmium, and high accumulation in shoot only under low concentrations of Cd stress.Studying heavy metal tolerance and accumulation characteristics of 4 species in genus silene through a pot experiment. Single and combined pollution of Zn, Cu, Pb, Cd were monitored by artificial addition of metals. The four species are S. uniflora, S.latifolia, S. coeli-rosa, S. orientalis. The results showed that maximum heavy metal absorption in shoot were all in single pollution treatments. The highest Zn and Cu shoot content appeared in S. orientalis, being 250.70 mg·kg-1 and 390.71 mg· kg-1 respectively. S. uniflora and S. latifolia had the largest Pb and Cd shoot content, being 30.63 mg·kg-1 and 1.74 mg·kg-1 respectively. S. uniflora, S. latifolia have showed strong tolerance to heavy metal. A germination experiment under Cd pollution showed that S. latifolia seeds could tolerate the stress of 12.5,25mg·L-1 Cd. But when the concentration reached 50,100mg·L-1, the seed could not be normal germination and growth.There were 7 cross combinations in hybridization among genus silene, including S.unifloraX S.latifolia, S.latifolia X S.uniflora, S.uniflora X S.colorata, S.colorata X S.uniflora, S.orientalis X S.latifoli, S.orientalis X S.uniflora, S.orientalis X S.jenisseensis. Only one suspected hybrid was obtained and its female and male parent were S.latifolia and S.uniflora respectively.Comparison of morphology, observation by scanning electron microscope and detection of the stigma receptivity were used in this study. The results showed that individual plant of Silene uniflora had fertile and male sterile flowers. Fertile flowers had the characteristics of pollen gradual presentation, protandry and dichogamy. Male sterile flowers were functional male sterility. Fertile flowers outcrossing index was 4, breeding system was outcrossing and partly selfing. Otherwise, the fruiting rate of fertile flowers was 31.71% through autogamy while the value of male sterile flowers was 0. The diameter of fertile flowers was larger than male sterile flowers. And fertile flowers had higher average number of seed per fruit and more probability of achieving larger seed number in the population. However, there were little differences between fertile and male sterile flowers in style length and numbers of ovule. The quantity ratio of male sterility and fertile flowers maintained at the level closed to 1 during full-bloom stage. In the early and later phase of florescence, male sterile flowers had more quantity than fertile flowers. Especially near the end of florescence, the proportion of sterile flowers gradually increased. |
