| 1The content of starch, sugar, protein, and hormones during the stages of frondescence, blooming, and vegetative growth were analyzed. The results showed that Rhizome and leaf nutrient accumulation occurred mainly in the period20days after blooming. The increase of ABA and IAA in rhizome is the symbol of China dragon developing into the vegetative growth stage. It is supposed that the decrease GA content in rhizome is a sign of lateral buds production. Low GA/ABA ratio is in favor of rhizome carbohydrate accumulation, the high GA/ABA ratio is in favor of leaf carbohydrate accumulation.2After spraying with CCC, BA and prohexadione calcium, the number of lateral buds was significantly increased. And the sequence of the effects is Prohexadione calcium, BA and CCC respectively. BA can promote the offset in a short and fast way. The response time of CCC was medium, and the buds grew slowly. Prohexadione calcium was the most effective method to enhance lateral buds production, and the buds grew fast. But the response time is much longer than others. We argue that all the three plant growth regulators inhibitor the synthesis of GA, which released from apical dominance, promote the germination and growth of lateral buds.3The relative electric conductivity (REC) and filed inspection were determined in leaves of six cultivars of Iris germanica, during the natural winter along with dropping temperature. The logistic equation was constructed based on the relationship between REC and temperature, then the semi-lethal temperature was determined. Malondial dehyde (MDA) contents.soluble protein contents and free proline contents were analyzed. The results showed that the index of chilling injury was intervenient1.20and3.65,and the range of semi-lethal temperature (LT50) was from-13.81℃to-5.73℃..’Cherry Falls’and’Bedtime Story’had high cold tolerance.’Brown Lasso’and’Black Swan’had medium cold tolerance.’China Dragon’ and ’Caligula’ had poor cold tolerance. The LT50decreased with the drop in temperature, the decrease of LT50was cultivar dependent. The decrease of LT50varied from1.46℃to6.51℃. The contents of soluble protein, free proline and MDA increased firstly, then decreased. 4By investigating on the specific field observation Iris speculatrix,its outcrossing index,pollen vitality and stigma receptivity,the ratio of pollen and ovule,artificial pollination and bagging experiments were performed for understanding the flower feature,blossom dynamic and breeding system. Results showed:The single plant florescence of Iris speculatrix’is3-6d, while group plants florescence last to35d. The flowers, setting on the same inflorescence,are monoecism. Male and female flowers mature at the same time, and the distance between anther and stigma is about3mm. The out cross index (OCI) is4,pollen-ovule ratio (P/O) is552. Taking the results of the emasculated, bagged and artificial pollination experiment together, it indicates that Iris speculatrix flower is a mixed-crossing system with out-crossing affinity as the main breeding form and concomitance out-crossing. Artificial pollination on fruit set rate is higher than the natural pollination.5By investigating on the specific field observation Louisiana Iris’Velvet memory’,its outcrossing index,pollen vitality and stigma receptivity,the ratio of pollen and ovule,artificial pollination and bagging experiments were performed for understanding the flower feature,blossom dynamic and breeding system. Results showed:The single plant florescence of ’Velvet memory’ is12-15d, while group plants florescence last to45d. The flowers, setting on the same inflorescence, are monoecism. Male and female flowers mature at the same time, and the distance between anther and stigma is about2.5mm. The blooming pattern follows the top first gold flower stems downward in sequence, and the other flower on top finally open; The out cross index (OCI) is4,pollen-ovule ratio (P/O) is1350. Taking the results of the emasculated, bagged and artificial pollination experiment together, it indicates that this is a mixed-crossing system with out-crossing affinity as the main breeding form and concomitance out-crossing. Artificial pollination on fruit set rate is higher than the natural pollination Confirmed that Velvet memory under natural conditions, the reproductive system affected floral organ structure and lack of pollinators, and rhizome propagation is an effective mechanism of its reproductive compensation. |
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