A Study On The Influence Factors And Regulations Of New Harvest Wheat After Ripening

This paper selected the new harvest the wheat Luomai 8 and Yunhan 618 as materials, determinated the changes of physiological quality of wheat in ripening period and the effects on different temperatures(15 ℃, 35 ℃), different humidities(RH:50% and 80%) and different gas components(vacuum, 98%N2 and conventional storage),explored the effects on 60Co-γ irradiation and chemical spraying(ethephon,GA) and other control measures. The results showed that:(1) There were no significant changes in the main physical index of newly harvested wheat during three months of storage, such as density, hardness, weight etc. but moisture content of grain decreased slightly during storage. The viability of the new harvest wheat is very high, but little lower with the extension of time. The new harvest of wheat germination potential is relatively low, and with the extension of storage time, it increased gradually. The germination rate was more than 90% after a month of storage, and then it remained at a high level.The wheat gluten content in storage period(30 days) relatively large changes in storage stage is relatively small. With the extension of storage time, the content of wet gluten of the wheat Yunhan 618 decreased slowly, but Luomai 8 did not decrease significantly. The total protein content of new harvested wheat basically unchanged during storage, and the content of free amino acids in storage decreased in the early stage. The content of wheat Yunhan 618 was stable after 30 days, while wheat Luomai 8 was stable after 60 days. Two kinds of amino acid content in Wheat during storage was changing about 200~400 μg amino acid nitrogen/g.With the extension of storage time,the fatty acid value of wheat increased, The content of reducing sugar decreased sharply in the storage period, then tends to be stable. While the non reducing sugar content and starch content remained unchanged during storage.(2) The period of newly harvested wheat ripening is closely related to storage environment. Effects of storage temperature on wheat ripening is most obvious, low temperature could effectively delay the new wheat harvest after ripening process. Vacuum or nitrogen storage but also to some extent delayed the wheat, and environment humidity on the small effect on wheat.The new wheat harvest of the alpha amylase and catalase activities were higher, with the extension of storage time, activity of amylase and catalase activity has been on the decline. It was faster decline in storage within 30 days prior to the time, after the enzyme activity decreased trend slowed down, basically stable. Low temperature(15 ℃) can maintain the wheat alpha amylase and catalase activity.(3) The influence of 60Co-γ radiation on wheat germination rate is related to the tolerance of wheat varieties and radiation dose rate.In general, for the low dose rate(8Gy/min) of the 60Co-γ rays, the dose of 20~130Gy could promote the germination of wheat seeds, and when the dose reached 200 Gy or higher doses will be germination of wheat. In high dose rate irradiation dose rate(18Gy/min), different doses of gamma irradiation on the seed germination of wheat in the influence of the difference is not obvious. Obviously, the low dose gamma ray irradiation can shorten the period of wheat, and the high dose, prolong the ripening stage of wheat. Ethylene and gibberellin can make wheat mature in a relatively short period of time, the germination rate increased, greatly shorten the ripening stage of wheat.(4) Low dose gamma ray irradiation can affect the activity of some enzymes in wheat grain. The activity of amylase in wheat grain after radiation were decreased, the gamma ray irradiation dose of 50~80Gy could reduce the activity of amylase, and after 60 days of storage in the irradiated group and the control group of wheat amylase activity difference is small; the grain of catalase activity increased after low dose irradiation, and delayed the normal activity of catalase activity of wheat trend.