The Study Of Breeding And Cultivation On Ornamental Sweet Potato Variety

Sweet potato is the important staple crops, it has been cultivated for more than 400 years in our country. Along with the society of development, the sweet potato is used in diversity aspects. Today, it has changed people's understanding of sweet potate thoroughly when it be used as ornamental plants. Ornament sweet potato as a garden plant be accepted and applied extensively by people, and it has been obtained good economic performance and social performance in the United States, Canada and other developed countrys. however, these nation's reseacher pay less attention to sweet potato's flower , which disadvantage to improve sweet potato's appreciation quality. The research of ornament sweet potato was just start in our country, and haven't found a good ornament sweet potato varieties. So we need to research of this aspect at further. In this experiment, the breeding and cultivation on ornamental sweet potato have been studied, and the results are as follows:1. 15 sweet potato varieties (or line) which have different appreciate characteristics respectively had been provided to evaluate. Among them, the varieties guifen No. 1 has the longest main caulis that make it better climb ability, but its flower time and the number of flower is general, which can be apply in green to fence or cultivate in pot when give it climb object. The line 1389 which has smaller leaf, better branches and leaves, more number of flower and longer flower period, and half-erecting plant-type, is suitable for potted cultivation. The line 2053 which has the most flowers and gorgeous floral color, but it's leaf is too big and leaf's shape is not good-looking, the flower footstalk length is shorter too, so the effect of the flower appreciate are hard to highlight and potted plant are worse. The line CL-7 which leaf's color is beauty, and has more number of flowers, bigger flowerand longer flowering period, but its footstalk is short and. The line 18 with beautiful color and leaf's shape, more number of flower, each period the number of flower are similar, flower footstalk is longer, and flower corolla is biggest, is the most suitable for potted cultivation in all sweet potato varieties or line. Other varieties or lines which hasve litter the number of flower, shorter flower period, are all unwell proper to potted cultivation.2. Gray correlative degree analysis was used to assess on result of the ornament sweet potato varieties selection, which can found the line 18 is the best to potted plant, its gray correlative coefficient is 0. 6617, the other varieties one by one are line 2053>line CL-7> guifen No. 1>line 1389> jinshan No. 630, with ornament result are similar with reality. Therefore, this method can be used to evaluate potted plant ornament sweet potato.3. The correlative analysis of various factors which effectd the number of flower showed that the important factors are the number of flower footstalk per plant and the flower formation rate. The number of flower related to the number of bud per branches and negative related to flower formation rate, which effected contribution rate on the number of flower. Because the number of flower footstalk per branches and the number of branches are obvious related, it can be think that the number of branches effectd the number of flower passes to effect the number of flower stalk per plant, therefore, the target of varieties selective should have more flower footstalk per branches and more the number of bud.4. Flowershape, color, fragrance of flower and the time of flowering which applied different fertilizer to the ornament sweet potato have no difference, but in the corolla diameter, corolla length, the flower footstalk grow and the number of flower have certain difference. The biggest impact factor is the number of flower. Among them, the number of flower at the treament N₂P₁K₂ and treament N₁P₁K₂ more 33.12% and 24. 16% than treament N₁P₀K₀, and were significantly different. Other treaments also have different degree improve compare with treament N₁P₀K₀, and all are not significantly different. When the number of bud and flower footstalk effect the number of flower, the number of bud and the number of flower footstalk of treament N₂P₁K₂ increase 16.67% and 7.73% respectively, compare with treament N₁P₀K₀. This can explain that increasing use N, P, and K are advantageous to increase the number of flower on ornament sweet potato , and the best resultion is to used with N, P, K together, and the effect of N, K fertilizer are better than P fertilizer .5. The correlative analysis of various factors which including the number of flower, chlorophyll content, root yield, branches number , leaf's area and the total day of flower, showed that each index is related to others, The relativity of which the number of flowers and chlorophyll content, root yield and leaf's area are, and also have stronger relativity with branches number and the number of flower, which showed that the effect of cultivation technique can benefit these index signs and can increase the number of flower. The chlorophyll content, root yield, branches numbers and the total day of flower would be increased when increaseing N, P or the K respectively, and the effect is less than N, P, K fertilizer combination, and more fertilizer, better effect.6. When different growth regulators and concentration were applied , flowershape, color, fragrance of flower and the life time of flower have no difference, but diameter of corolla, corolla length, length of flower footstalk and number of flower have certain effect. Among them, the effect of plant growth regulators CTK was best for flowering on ornament sweet potato, it was not only useful to increase the number of flower of sweet potato, but also increase day of flowering and the number of flower per day. And CTK concentration for sweet potato flowering are 0. 03-0.12 ppm, and the effect was best to sweet potato flowering at 0. 06ppm. with this treatment , the number of flower per plant increase 74. 67, and the start time of flowering and the end of flowering were be 11 days aheade and 12 days delay respectively.