| Narcissus tazetta var.chinensis is Amaryllidaceae perennial bulbous herb,has a high ornamental value.In this study,3-year-old Chinese narcissus bulbs was used as experiment material.The bulbs were pelleted and stored at 5℃,15℃,25℃,35℃,and room temperature until planting.The morphological observation,measurement of physiological and biochemical indices,and molecular biology studies were studied from different perspectives.The effects of storage temperature on the growth and development status of Chinese narcissus bulbs provide the basis for future research on the temperature and development mechanism of Chinese narcissus bulbs.The main results are as follows:1 Changes of bulb carbohydrate in Narcissus tazetta var.chinensis at different temperatures during storageSoluble sugar and starch content of Chinese narcissus scales-and main buds at different temperatures were measured.It was found that the changes of starch content in inner and outer scales and main buds at different temperatures were basically consistent.During the storage,the soluble sugar content of the scales and the main buds in the Chinese narcissus showed a slowly increasing trend.The sugar content of the outer scales was lower than that of the inner scales and the main buds.This was due to the fact that with the prolongation of storage time,the bulb nutrients of Chinese narcissus during storage were basically the same.Stored in the inner scales and the main buds for the differentiation of Chinese narcissus buds,which provides nutrients and energy for the growth and development of Chinese narcissus in the later period.2 Analysis of morphological changes of bulbs in Narcissus tazetta var.chinensis at different temperatures during storageThe morphological observation of the main buds of Chinese narcissus observed that the main buds stored at 15℃ and 25℃ had a faster growth and the growth rates at 5℃,35℃ and room temperature were slower.20 days after storage at 5℃ and 35℃,the tip staining was deeper,cells were denser,cell viability was apparent,5 d after storage at 15℃ and 25℃,the flower bud differentiation at room temperature began to start at 25 d after storage.The tip of the Chinese narcissus growth cone stained deeply.With the extension of storage time,the degree of differentiation of the Chinese narcissus bud continued to deepen,but the overall progress was slower than that stored at 25℃.Stored at 25℃ and room temperature showed flower buds,and leaf buds remained at 5℃,15℃ and 35℃.Observing the main buds and scales of Chinese narcissus starch granules,the results showed that the number and size of starch granules in the outer scales are higher than that of the main buds,and the number of starch granules was significantly reduced when the main buds of Chinese narcissus were established.The number of starch granules stored at 5℃ showed "down-up-down" trend.At 15℃,the morphological development of Chinese narcissus buds was faster,so the starch granules were sparsely distributed,and most of them were concentrated on the bulb try,they were stored at 25℃ and at room temperature.As the degree of differentiation of flower buds deepens,the number of starch granules decreases significantly.The amount of starch granules at 35℃ for 5-10 d is basically consistent,and the amount of starch granules is rare 15-25 d after storage.3 Changes of Endogenous Hormone Contents Narcissus tazetta var.chinensis Buds at Different Temperatures during StorageThe content of ABA was related to the temperature.ABA was conducive to promoting the development of Chinese narcissus morphology;the IAA content of the buds of Chinese narcissus showed a decreasing level overall,but remained at a certain concentration as a whole;The contents of JA stored at 5℃,15℃,and 25℃ were overall higher,and JA content was lower at 35℃ and at room temperature.This may be due to the effect of high temperature environmental protection during storage.SA content at different temperatures showed "down-up"trend,which may be related to storage time and morphological development;The high ZR content of 5℃ may be affected by low temperature.The content of main buds stored at 15℃ and 25℃ is slightly higher,and the room temperature content is lower.The storage temperature is closer to the temperature suitable for the growth of narcissus,and the ZR content is higher.High,the faster the main bud grows.4 Effects of Different Temperatures on Gene Expression of Bud Dormancy and Bud Differentiation in Narcissus tazetta var.chinensis during StorageThe gene expression analysis of bud dormancy and bud differentiation in Chinese narcissus,NtFTs gene,ABA and GA synthesis and degradation related genes,flower bud differentiation related gene under different temperature control gene expression inconsistent.The effects of NtFT3 and NtFT4 genes under different temperature control were obvious.The NtFT gene was only expressed at low storage temperature at 5℃,but other storage temperatures were high.There was no consistency in the changes of the expression levels of related genes in the ABA synthesis pathway.The expression of NtAA03 and NtNCED genes at different temperatures had a significant effect,and the expression levels of NtZEP and NtABA2 genes had no significant effect.The expression of NtGA3OX,a gene related to GA synthesis,showed a decreasing trend at different storage temperatures.The NtGA2OX gene,a gene related to GA degradation,was stored at different temperatures at low levels,which may impede the synthesis of GA.The ABA and GA synthesis-related degradation genes involved in the development of Chinese narcissus bud morphology.NtAP1 gene storage at different temperatures had a significant effect on the formation of Chinese narcissus buds,but had no significant effect on the development of leaf buds.NtAP3 gene expression was volatile at different storage periods at 5℃.The expression of this gene has increased at 15℃ and 25℃.The expression of NtP1 gene in storage at 5℃ and 15℃ showed a rising-descending trend.The expression of NtPI gene at 25℃ increased overall and showed an upward trend,indicating that theNtPI gene had a significant effect on flower bud differentiation during storage at this temperature.Differences in expression of NtLEAFY genes stored at different temperatures.The expression level of NtLEAFYgene at storage at 25℃ showed an upward trend,which may be ahead of the flowering period.The NtSVP gene at 5℃ was stored at a low level and the expression at other temperatures was higher.The storage at 25℃ was higher than that at room temperature,probably because of the obvious regulation of flower bud formation by NtSVP gene. |
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