Studies On Evaluation And Germplasm Innovation For Some Plant Resources Of Iris L.

The objective of this paper was to research in the fields which were pay close attention in irises application at present such as the drought resistance of some ornamental iris native to China, the isolation and identification bacterial soft rot disease of some introduced Iris, dwarf and bacterial soft rot resistant cultivars breeding and utilization of ISSR molecular markers for identification, analysis and evaluation of genetic diversities and resources preservation of Iris. The results were as follow: 1. Studies on the drought resistance of some ornamental Iris species1.1 Based on the correlationship between the regerminating percentage and the drought resistance of the 5 Iris species by mortal drought treatment and then watered, it is revealed that the drought resistance of Iris species from strongest to the weakest was: I. germcmica, I. tectorum, I. pseudacorus, I sanguined, I. lactea var. chinensis. I. germanica was the most drought tolerant species, being watered after 35and 48 days drought treatment, the germinating rate of I. germanica was 83.33% and 73.68% respectively. Next, I. tectorum, 52.9% and 37.5% respectively. I. lactea var. chinensis, the control just 23.8%andl4.8%. I. pseudacorus was often planted as water plants in the garden before, the results of the experiment also showed that it could not only be planted in the soil and but also be a more drought tolerant plant.1.2 The correlationship between physiological parameter changes and the drought resistance of five Iris species was discussed. It was showed that the characters and regulating change of8 physiological parameter such as relative water content, the chlorophyll content of the leaves, the stability of cell membrance and soluble materials regulation were close related with the drought resistance of 5 Iris species, and that was the same with the mortal drought treatment in each species.2 Studies on the isolation, purification and identification of the bacterial soft rot pathogenic bacteria in Iris L.The pathogen isolated from 7m germanica L.was identified as the bacterial soft rot pathogen, Erwinia chrysanthemi Burkhdder, Me Fadden & Dimock based on bacteriamorphological, pathogenicity tests, cultural, and physiological and biochemical properties.3 The breeding studies on the dwarf and disease resistant cultivars of Iris germanica L.3.1 Due to the cultivars of/, germanica L. used as parents are heterozygotes, therefore, some characters, especially flower colors were different in first filial generation. The flower colors of individual plants obtained in first filial generation were same, similar and some totally different with parents. It was also showed that the heredity of the flower color of purple was much stronger than yellow, pink, red and white in intraspecies crossing of /. germanica L., and the individual plants with purple flowers were much more than the individual plants with other colors in filial generation.3.2 The heredity of tall character was much stronger than that of dwarf ones, and the number of plants with different height of the filial generation reduced from gradeIIIto grade II and gradeIVand grade I . The results showed that the dwarf plants of I. germanica L. could be obtained through repeated backcrossing to the dwarf parent.3.3 The hybrid generation survival rate of the combination with one parent of bacterial soft rot resistant grade 1 were 26.3%~28.7% higher and the percentage of diseased plant 17.6-20.3% fewer than that of the control. A few bacterial soft rot resistant individuals have been obtained by using a bacterial soft rot resistant parent to cross with elite parents. The resistance of the filial generation had been proved through 4 life circles in the plots with pathogenic bacteria. The results showed that bacterial soft rot resistant individuals have been obtained by using a bacterial soft rot resistant parent to cross with elite parents.3.4Fives hybrid combinations for dwarf breeding and 3 for disease resistant were carried out for Iris germanica L. and eight new dwarf individual plants and five bacte...