| Gazania rigens L.is a perennial herbaceous plant.It has rich colors,colorful ornamentations,unique patterns of flowers,and inflorescence decorated with very similar medal design.Therefore,it has good agronomic characters and high ornamental value,which can be used as cover flower of landscape architecture and household gardening.In this paper,three kinds of Gazania rigens varieties introduced from Netherlands and the United States were used as experimental materials,and the seed adaptation,biological characteristics,environmental adaptability,cutting propagation,ornamental characters as well as landscape application were studied after two years of introduction and cultivation experiments in Suzhou.In order to select new varieties suitable for Suzhou,the analytic hierarchy process(AHP)was applied to evaluate the imported chrysanthemum on this basis.The main results were as follows:1.The phenological and morphological features of the imported varieties of‘White Flame',‘Yellow Flame' and ‘Red with Ring' were investigated and observed.The results showed that the flowering period in Suzhou is concentrated from early March to mid to late May,and the single flower blooming for 8 to 14 d,and the diameter of the flower is 9.23 to 12.94 cm,each of which showed good ornamental traits.2.The changes of proline,malondialdehyde,chlorophyll and relative conductivity in G.rigens leaf were measured after 24 h of artificial low temperature treatment of 6?,4?,2? and 0?,2?,4? in three kinds of G.rigens varieties.The cold resistance of 'White Flame' was strong,which mainly manifested in the change of malondialdehyde in vivo and low relative conductivity,and the content of proline and the accumulation of chlorophyll were higher.3.The changes of physiological and biochemical indexes and photosynthetic rate of three cultivars under drought stress were discussed.The results showed that ‘White Flame' the photosynthetic rate decreased slowly and the amount of proline accumulation was significantly lower than that of the other two varieties after 18 d stress.The ‘Yellow Flame' has the highest increase in malonaldehyde.But in terms of apparent morphology and the change of osmotic material,‘Yellow Flame' has the weakest drought resistance ability.4.To discuss the reproductive capacity of the imported G.rigens,the cutting propagation experiment was conducted on three kinds of G.rigens in early May(flowering period).The rooting rate of the three G.rigens species can reach more than 60% and can be transplanted after 30 days by using peat as cutting matrix.A one-year storage experiment was carried out in different temperature environments for the G.rigens seeds,which showed that the germination rate and index of seeds stored at low temperature were significantly higher than those stored at normal temperature.5.A comprehensive evaluation model suitable for G.rigens was established by using analytic hierarchy process.According to 19 evaluation indexes,three G.rigens species were evaluated comprehensively.The results indicated that the ‘White Flame' and‘Red with Ring' had good performance,presented as high ornamental value and adaptability.They were suitable for promotion in Suzhou.The ‘Yellow Flame' had high ornamental value,but it has poor adaptability simultaneously.Protective measures should be increased when it was planted.6.Combined with the application principles of groundcover plants in landscape construction,several forms of G.rigens applied in Suzhou were summarized.Besides used as potted plants,ground cover landscaping,flower beds and flower borders can also be constructed. |
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