Study On Introduction And Selection Of New Varieties Of Dried Jujube In The Arid Region Of Ningxia

The testbed of the current study was located in the arid zone of middle Ningxia.In order to enrich the dried varieties of local jujube,the 5-year-old 'Tongxinyuanzao' was used as rootstock in this experiment with adopting the grafting mode of high grafting.One-year-old branches of 7 different dried varieties of jujube were grafted,and the phenological observation of different varieties of jujube was carried out with 'Tongxinyuanzao'as the control.The growth characters and photosynthetic basic characters of each dried variety of red jujube and the fruit quality were measured and studied,with the data of different indexes of jujube being analyzed and evaluated by principal component analysis(PCA).The results were given and displayed below.1.All of seven different dry varieties of jujube took place in mid-late April,in the sprouting stage of jujube with jujube 'Huping' the earliest yet and 'Yuanling' the last;the period of leaf development was generally concentrated from April to mid-May.The jujube 'Xiangzao' was the earliest to enter the beginning of flowering while the fruit setting period of'Yuanling' became the earliest.The mature stage of 'Tongxinyuanzao' was the earliest,and the fruit setting duration of each variety was the longest;the jujube of each variety began to leave leaves in early October and ended the deciduous leaves in the middle and late October.There was a little difference in the annual growth period of each variety:the annual growth period of 'Jingu' jujube was 181 days,followed by Tongxinyuanzao','iLinhuang 1#'and 'Yuanling'jujube,and the smallest growth period was 171 days of'Banzao'2.Among the growth indices of 7 different dried jujube varieties,'Tongxinyuanzao'as a native variety was found to be obviously better than other varieties in the index of tree height and crown width.The maximum main branch length,maximum main branch diameter and new shoot growth index of'Linhuang 1#' were all recorded higher than those of the control,indicating that 'Linhuang 1#' had a stronger branch forming capacity than the 'Yuanling' jujube with the smallest of the three indices.The value of the new shoot growth index of'Yuanling' jujube was the lowest among the three indexes while the value of the new shoot growth index of 'Linhuang 1#' was higher than that of the control.The results above showed that the growth ability of branches of' Yuanling' jujube was weaker than that of other varieties.3.Among the photosynthetic indexes of 7 varieties of dried jujube,the indexes of leaf length,leaf width,leaf weight and leaf area of 'Linhuang 1#' were higher than those of other varieties in general,known as 20.40%,21.74%,55.69%and 47.49%that were higher than those of 'Tongxinyuanzao'respectively.The 'Yuanling' jujube of chlorophyll was the highest yet that of 'Tongxinyuanzao'was the lowest.There remained significant differences between different varieties and 'Tongxinyuanzao';however,in the photosynthetic rate determination,all varieties were observed to be smaller than that of the control.4.Among the fruits of different jujube varieties,the single fruit weight and flesh weight of'Tongxinyuanzao' were 17.23 g and 16.235 g respectively.The 'Yuanling'jujube was the smallest as 5.33 g and 4.883 g respectively.Moreover,the edible rates of each variety were above 90%,with the largest as 'Jingu' jujube reached 95.75%.5.In order to avoid the influence of different units of measurement on the final scores,the data of 23 indexes of 7 different dried jujube varieties were at first standardized by normalization method.Then the main principal component factors were screened out by PCA,followed by the operation of comprehensive evaluation score of each dried variety.The results from the current study reveal that the characteristic roots of the first four principal components were more than 1,and the cumulative contribution rate was 95.23%;that is to say,most of the information of the original index of jujube could be reflected.The final comprehensive evaluation scores were in sequencce as follows:Linhuang 1#>Jingu>Hupingzao>Tongxinyuanzao>Banzao>Xiangzao>Yuanling.