| Sugarcane is an asexual propagation crop using stem buds. Multiple pathogens, especially ratoon stunt disease, mosaic virus and so on, can infect repeatedly and accumulate in plants after years of continuous asexual seedcane planting, and it is hard to eliminate the pathogens by chemicals. Therefore, the superior characteristics of elite varieties retrograde gradually, which can cause yield decline with reaching 30% in serious regions. So far, double-buds sett planting (30-40 cm) is widely used in China. The seedcane sett with double buds accounts for about 10% sugarcane yield (6-7 t/ha), that is a big loss for sugar production. Besides, it needs a lot of labor to store and transport the seedcane, and it needs high cost to plant the seedcane accounting for about 25% the total cost of the sugarcane production. The cane buds are easily damaged during storage and transport, causing lower germination rate. In this study, the healthy seedcanes of sugarcane variety ROC22 were chosen as the plant material to screen suitable length of single bud seedcanes and effective seedcane coating chemicals, investigate the effects of different storage temperature and field performance of the seedcanes soaked by seed coating chemicals. The results are as follows.1. Healthy canes were cut into different length with single bud:1,2,3,4,5 and 6 cm, respectively. Treatment of soaking with seed coating medicals was done with water coating as control. All single bud setts were grown under sand culture. The germination rate of the chemical treatment was higher than control. The plant height, aboveground and underground biomass, and photosynthesis of seedlings were higher than control after 30 days. The germination rate, plant height, aboveground and underground biomass, and photosynthetic indexes were significantly greater in the single bud setts of 5 cm in length, than in those≤4 cm, but there was no significant difference with those of 6 cm. Therefore, the appropriate length for single bud setts is recommended as 5 cm, which can decrease the loss of sugarcane yield used for seedcane, and is good for germination and growth.2. The single bud setts of 5 cm in length were chosen to be soaked in seed coating chemicals. After that, the single bud setts were called ’plene’. The plene were stored at 22 and 13 ℃, respectively. It was found that the moldy rate, and changes of water content and total weight were not significantly different under the two temperatures, so the plene could be kept in room temperature (22 ℃). The results also indicated that seed coating chemicals could inhibit the growth of pathogens, keep moisture of the seed canes, improve the resistance of seed canes and promote the germination of buds. The plene were kept for 1,3, 5 and 7 d at 22 ℃ in summer (June) and winter (December), respectively, and the results showed that the germination rate were higher in the plene soaked with seed coating chemical called Maishuping and Pulimeng than those soaked with other chemicals. So Maishuping and Pulimeng were good for making plene.3. The single bud setts of 5 cm soaked with Maishuping and Pulimeng were kept for 1, 3,5 and 7 d at 22 ℃, and then planted in greenhouse. Photosynthesis index were determined in 150,180 and 210 d after planting, respectively. Agronomic traits and chlorophyll content in leaf+ 1 were determined at late growth stage. Based on the above parameters, the seed coating chemical Pulimeng was found the best for sugarcane plene production. |
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