| There are rich wildlife resources of Iris in China which have the beautiful figure. The preconditions are the research of the biological characteristics,the ontogenesis rhythm and the propagating. I.loczyi,I.songarica,I.potaninii and I.lactea were herborized successfully from the Qinghai province of China. Through the seed germination characteristic, the ontogenesis rhythm, the blossom and pollination characteristic, the root and leaf dissection structure, the photosynthesis characteristic research and the nuclear type analysis, get conclusions as follows:1. The seeds of the four Iris species have the deep dormancy, and seed dormancy can't be removed by GA3,nature stratification and cold stratification. The seed germination rate of I.loczyi,I.songarica,I.potaninii and I.lactea can be raised from 0 to 12.22%,52.22%,16.67%,33.33% effectively through removed the seed capsule. Removed the endosperm of I.loczyi,I.songarica,I.potaninii and I.lactea,germinate rate raised 7.14%,58.33%,47.22%,72.22%. Removed the endosperm of I.loczyi ,germinate rate raised 28.57% by GA3. The best concentration is 0.1mg/lGA3.The suitable temperature of germination was 25℃for I.loczyi and I.potaninii. The suitable temperature of germination was mimetic temperature for I.songarica and I.lactea.2. The four Iris species seedlings were all cotyledon stay soil.The ontogenesis rhythm study on I.loczyi,I.songarica,I.potaninii and I.lacteal indicated that the growth rhythm could be fitted by"S"curve.The four growth periods were divided for the seedlings by using the cluster analysis of series samples:Emergence phase of seedlings;Initiation phase of seedling growth;Prosperous phase of seedling growth;Later phase of seedling growth.The production of prosperity period was about 60%-90% from July to October.It had two vigorous growth periods for the four Iris species adult plant.The first concentrated the period after flowering.The second was in the latter of September.3. The florescence of I.loczyi,I.songarica and I.potaninii were the early of year.The pioneer of florescence was I.potaninii which blossomed from the latter of Mar to the early of April. The florescence of I.loczyi was the latter of April. The florescence of I.songarica was from the latter of April to the early of May.Flower buds of I.loczyi differentiated rapidly in July and October, and early in September flowering organ had formatted. Flower buds of I.potaninii differentiated rapidly in June, and in early July flowering organ had formatted.In August, flower buds of I.songarica differentiated rapidly, and at the beginning of September flowering organ had formatted.4. The root system of the four Iris species were fibre and assumed vertical distribution. The number of the first formed xylem of I.loczyi, I.songarica and I.potaninii was 10, 9and 4. Mesophyll cell differentiated for palisade tissue and spongy tissue in I.loczyi,I.songarica and I.lactea, except I.potaninii.5. Early in August, diurnal changes in net photosynthetic rate(Pn) of the four Iris species were a typical bimodal curve. The light saturation point(LSP) of I.loczyi,I.songarica,I.potaninii and I.lactea was 43.37,49.10,38.47,31.96μmol·m-2·s-1, whilst the light compensate point(LCP) was 574.11,370.15,450.27,346.11μmol·m-2·s-1. The four Iris species were a typical light favor plant.But I.potaninii was a shade sustainable plant a little. And I.lactea was a shade sustainable plant.6. The number of chromosome of I.songarica was fourteen. The karyotype formulae of I.songarica was 2n=14=6m+8sm(2SAT), belonging in Stebbins's 3A type.Grasping the plant growth process and biology characteristic, can provides the basic research for the garden application, the breeding and expands numerous.
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