| "Gouqizi" has been used in traditional Chinese medicine. Chinese Pharmacopoeia took L. barbarum as only original plant of "gouqizi", which belong to the genus Lycium in the family Solanaceae is a perennial shrubs, and dry fruits is the main medical parts, which was rich in Lycium barbarum polysaccharide(LBP) and total sugar. Due to dry fruits is not only the main medical parts but also is the organ in which the major components accumulate, the indexes of fruit size and major components contents were very important to evaluate the quality of the fruit of Chinese wolfberry, while the studies, which were the morphology, structure and development of fruits, the relationship between structure and sugar accumulation in fruit and the effects of soil microenvironments on the yield and quality of fruit, were not been studied at present. Anatomical, physiological, histological and phytochemial methods were used to investigate the structural features and the development of fruit of L. barbarum, the relationship between structure and primary photosynthesis production and medical components accumulation in fruit and the effects of soil factors on sugar accumulation, and different irrigation amounts on sugar accumulation and its suitable irrigation amounts. The main results showed that:The fruit growth curve of L. barbarum belongs to double "S" curve, and could divide into three stages. The first rapid stage spanned 8 days after blossom, then, it followed by a slow growth stage (8-24 days after blossom),and the second rapid growth stage (24-34 days after blossom). While the seed growth curve of L. barbarum was not only single "S" curve, but also double "S" curve. The first rapid stage of fruit was also the first rapid stage of seed, but the ratio of seed growth increasing was more than that of fruit, and the increasing of endosperm in seed was notable. During a slow growth stage of fruit, the increasing ratio of length and width were lower than those of seed in the first rapid stage, and embryo differentiation took place in seed during this period. During the second rapid growth stage, the volume and weight of fruit significantly increased, on the contrary, the length and width were almost not increasing, only embryo gradually grew up. These above results indicated that the morphology development of fruit was regulated and controlled by the seed development. The starch grain was not observed in chloroplast, the reason which caused were lower photosynthetic pigment content, without stomatal apparatus in pericarp and weak photosynthesis of fruit. The chloroplast converted chromoplast in ripe fruit. The amyloplast enriched much more starch grain before veraison stage(24 days after blossom), but starch grain almost disappeared during the second rapid growth stage.The starch was a transient form of carbohydrate accumulation during fruit development, which was available to form sugar concentration gradient between "source" and "sink" and accelerate sugar unloading from phloem and played an important role in maintain the sink capacity in early phase fruit. With the volume of fruit increasing, the sink capacity also became more and more stronger, and starch was degraded into reducing sugars by the action of amylase and accumulated in fruit parenchyma cell.The sugar accumulation mainly occurred in the form of hexoses, with the ordering of contents in ripe fruit:fructose> glucose> sucrose. Invertase activities were the key enzymes to control the hexoses accumulation in fruit, and the increasing of invertase was available to enhance the sink metabolism in later stage of fruit development.With the fruit growing, the sieve plate with large and much sieve pores, where active substance transport was observed in SE. Most, if not all, of the CC were transfer cells. Numerous plasmodesmata were observed between SE and CC (SE/CC), but there were almost no plasmodesmata between the SE/CC complexes and phloem parenchyma cell. Plasma membrane invagination was observed in adjacent between companion cell and phloem parenchyma cells. There was a symplasmically isolated between the SE-CC complex and its surrounding cells over the fruit development, which was available to sugar phloem unloading by apoplast pathway. Numerous plasmodesmata were also observed between the phloem parenchyma cells, On the contrary, there were almost no plasmodesmata between phloem parenchyma cell and fruit parenchyma cell and even between fruit parenchyma cell. The larger intercellular space among the fruit parenchyma cell and apoplast space caused by cell wall and plasma membrane invagination, which were in favour of sugar post-phloem transporting by apoplastic pathway. Vesicles were observed to participate in assimilates unloading and transporting.The content of LBP was positively correlated with those of total sugar, glucose and fructose, while on the contrary, negatively correlated with that of sucrose in different development stage fruits. Besides, the content of total sugars was positively correlated with those of glucose, fructose and sucrose in different development stage fruits. These results indicated that sucrose metabolism plays an important role in the formation of LBP and total sugars in the fruit of L. barbarum.The polysaccharide content of L. barbarum in Ningxia region (Ningqi No.1) was higher than not only those of the same variety in Hebei, Xinjiang and Inner Mongolia, but also those of different varieties (Jingqi No.1) in Xinjiang or species (Jiaqiguo, L. chinese) in Hebei. In terms of medicinal utility, the quality of L. barbarum in Ningxia region was superior to that of its cospecific counterparts in other regions as well as that of L. chinese. The soil HCO3- was significantly correlated with the content of glucose and fructose contents. The content of glucose was found to correlate significantly and negatively with Ca2+and with Mg2+. The content of soil total salt was non-significant and positive correlated with LBP and with total sugar. The content of LBP was significant and positive with Ca+and with Mg2+. The total sugar was significantly positive correlated with soil pH, Cl-and with Na+. These results showed that soil total salt played an important role in growth and development of L. barbarum. Meanwhile the content of total sugar was significantly and negatively correlated with soil organic matter and available nitrogen. Therefore, the contradiction between the yield and quality should be coordinate properly, so as to improve the quality of L. Barbarum.With the increasing of irrigation amount, the contents of glucose, fructose, sucrose and polysaccharide were decreased, but polysaccharide content was not existed significant difference under 0,450 and 900 m3 hm-2 irrigation amount per month. When the irrigation amount per month was less than 900 m3 hm-2, fruit yield was increasing, while irrigation amount more than 900 m3 hm-2, there was no significant effect of irrigation amount on the fruit yield.With the increasing of irrigation amount, the vessel diameter of root became more and more wider, and the more significant positive correlation existed with them. Vessel frequency and ratio of vessel area to secondary xylem area were the highest under 900 m3 hm-2. The ratio of fibre area to secondary xylem area decreased at first and then increased, and the value was the lowest under 900 m3 hm-2. The ratio of parenchyma cell area to secondary xylem was non-significant positive correlation with different irrigation amount; Vessel diameter of stem was the highest under 900 m3 hm-2. The more significant negative correlation was displayed between them. The ratio of vessel area to secondary xylem area was the highest under 450 m3 hm-2. The ratio of fibre area to secondary xylem area became more and more increased, and the significant positive correlation existed with them. However, the change of the ratio of parenchyma cell area to secondary xylem was opposite to fibre in stem; The ray frequency of root and stem were decreased with the increasing of irrigation amount, and displayed the more significantly negative correlation between ray frequency and irrigation amount, respectively. The decreasing of the ray frequency of secondary xylem indicated the weakening of horizontal transportation function in root and stem. Therefor, with the increasing of irrigation amount, the number of molecules of the structures and composition of secondary xylem of root and stem of L. barbarum changed.900 3 hm-2 irrigation quato per month could cause the increasing of vessel diameter increase, but reducing the frequency, so as to maintain suitable efficacy and safety of water system is in L. barbarum.When the irrigation amount per month was less than 900 m3 hm-2, the leaf area, leaf thickness, palisade tissue thickness, CTR, net photosynthetic rate (Pn), leaf intrinsic water use efficiency (WUE) and Ls all significantly increased with irrigation quota per month, while stoma density and Ci showed reverse trend. When the irrigation amount per month was more than 900 m3 hm-2, Ci increased with the irrigation quota per month whereas other indexes showed the contrary trend. There was no significant effect of irrigation amount on leaf area and stoma density. Highest transpiration rate and Gs were recorded under irrigation quota 450 m3 hm-2 per month. Therefore, in terms of saving water,900 m3 hm-2 was suitable irrigation quota per month for L. barbarum. |
