The Effects Of Physiological Age Of Potato Microtubers On The Content Of Sugars And Soluble Protein And Plant Development In The Field

Potato (Solarium tuberosum L.), originated from South America, is one of the oldest crops cultured by human. Today potato is one of the most important food crops in the world, especially in developing country. The planting area of potato in China is first place in the world but the output per hectare is lower than the average level of world. When potato reproduced in the field several generations, the variety characteristic will lost due to the accumulation of virus in the potato tubers. So producing healthy and virus-free seed tuber is the most important task for potato industry. Recently we have taken great achievement in microtuber production, this is a promising technology for potato seed production system. But, at present, papers which about the performance of microtuber in field is fewer. The results of former researchers showed that the poor outcome of microtuber is the largest obstacle for it application. To look insight into the possibility of microtuber as seed tuber in field production, we carried out this experiment to analyze the effects of physiological age on microtuber performance in farm. The main results obtained as bellow:1. With the prolongation of storage, reducing sugar and total soluble sugar content of microtuber decreased in the different temperature conditions. In higher storage temperature the changes are great. The storage temperature had significant effects on the amount of sugar content in microtubers. The relationship of physiological age(y) and sugar content(x) could be described using the function y=ex.2. During the storage, soluble protein content of mirotubers keeps increase. In the late of storage the difference between different treatments became significant. Function y=ex can be used to predict protein content(x) of different physiological age(y) microtubers.3. For different variety, physiological age had different effect on microtubers emergence. The difference of early emergence of variety El was significant, but at last the percentage of emergence was almost the same between treatments. The difference of emergence in variety N552 can be seen in all stages.4. The difference of harvest index and plant high between El and N552 is significant, but physiological age wasn't. There was no difference of plant canopy and photosynthesis between varieties and physiological ages.5. Variety and physiological age had no effects on tubers and plant haulm output in early stages of plant development. Dry matter content of tubers and haulm had no statistical discrepancy between different physiological age and variety.