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Study on the Characters of Chinese Cherry Flower Bud Differentiations and Flowering

Author: LiYongQiang
Tutor: GuoWeiDong；ChenWenRong
School: Zhejiang Normal University
Course: Botany
Keywords: Cherry Flower bud differentiation Chilling Requirement Pollen mother cells Phenological phases
CLC: S662.5
Type: Master's thesis
Year: 2010
Downloads: 176
Quote: 0
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Abstract

Chinese cherry (Prunus pseudocerasus Lindl.) As important types of fruit trees, but the less the related research reports. Flower bud differentiation fruit trees to the reproductive phase transition from vegetative growth stage, it is one of the vital phenomena of life in the life cycle of fruit trees. Sleep is a perennial deciduous fruit trees to withstand adverse environmental an effective process. Deciduous fruit trees to the next cycle of growth and development must go through an important stage to meet the chilling requirement to successfully complete the natural sleep, sleep has become the constraints that limit the development of fruit trees cultivation, but also limits the development of deciduous fruit trees to the warm tropical regions. Cherry flowering phenology of early flowering susceptible to low-temperature hazards, this is one of the main reasons for cherry production in the Zhejiang region is low and unstable. Therefore, in areas vulnerable to late spring invasion, select the late flowering varieties open field cultivation, so as to avoid unnecessary losses. In this thesis the cherry flower buds throughout the development process, including differentiation, dormancy and germination. Defined in the Zhejiang region of China cherry flower bud physiological differentiation and morphological differentiation of physiology and morphology. Abstract of the determination of leaves and physiological indicators. Glandulifera cherry 2009 flower bud physiological differentiation period July 5 to July 25, the flower bud morphological differentiation began in late July, the entire differentiation period can be divided into bud differentiation stage, calyx differentiation stage, petal differentiation stage, stamen differentiation and pistil differentiation stage 5 period before July 15, has not yet started morphological differentiation, differentiation of flower primordia and bracts primordia of first appeared in the July 15; calyx differentiation period in August; corolla primordia differentiation of this period is generally from early September until mid-September. Into the petals of flower buds differentiation stage of differentiation to accelerate the process quickly transition to the next period. Stamen first appeared in the beginning of September, early October in addition to a small part of the flower buds in the stamen differentiation stage, and all the rest into the pistil differentiation stage. Throughout the differentiation time lasts approximately 70 d. Through the the field temperature logger for three consecutive years on a short handle cherry flower bud chilling requirement of low temperatures in winter and Jinhua accumulation of statistical research. The results show that: the short handle Cherry Flower Buds state to break dormancy in late December. Through the comparison and analysis of the three-year data, the Utah model the statistical results than 0-7.2 ° C ≤ 7.2 ° C model is more stable, estimated the Brachypodium cherry chilling requirement of about 300 CU; statistics also showed that Jinhua winter cold temperature accumulation 1000 CU. Morphology and Anatomy of Zhejiang floral organ development in the region Chinese cherry Sleep process throughout the hibernation period, the flower buds internal cells by division, expansion and differentiation has led to the formation of organs. The stamen most obvious development, development to the vascular tissue connected to the the anthers structure of four microsporangium, microspore mother cell stage anther development to break dormancy. The same night temperature conditions, a set of six different daytime temperatures to study the impact of different temperatures on cherry flower buds germination floral organ development process. The results show that the temperature on the germination of sweet cherry flower buds form of anatomy and physiology have a significant effect. The higher the temperature, the faster the flower bud development, flowering sooner. 35/10 ° C treatment conditions, the vast majority of flower buds reach the inflorescence visible period will stop growing, not the normal flowering and fall off; 30/10 ° C treatment significantly inhibited the development of the corolla, stamens and pistils, anthers not normal cracking loose . Temperature before anther development to the pollen mother cell stage. The daytime temperature above 30 ° C for 15 days, pollen mother cells are unable to carry out normal meiosis lead to male abortion. 25/10 ° C treatment meiosis to form tetrads, but pollen grains formed part of the abortion. Cherry flower buds in the six temperature treatments by measuring malondialdehyde (MDA) content, and to explore the different temperature membrane lipid peroxidation. 35/10 ° C, 30/10 ° C, 25/10 ° C three treatments, the content of MDA are in the the inflorescence visible after began to increase; 20/10 ° C, 15/10 ° C, 10/10 ° C for three processing relative stability. That the daytime temperature is higher than 25 ° C caused damage of membrane lipid peroxidation. The three cultivars Zhejiang mountain cherry varieties 'Brachypodium', 'Black Pearl', 'olecranon' flowering phenology of floral organs, fruit traits was observed. The results showed that: Hou period of three varieties of flowering significant difference in flowering 'olecranon' earliest 'short-throw cherry' latest. Different varieties of pistil length and ovary was no significant difference in diameter, petal color, shape, corolla size difference is significant, the amount of pollen there are also significant differences. Corolla diameter and fruit weight there is a significant correlation. Short handle cherry pollen germination and pollen tube growth rate, the study showed that sucrose is obviously to maintain the osmotic pressure of the external environment of cherry pollen, add the appropriate amount of boric acid in favor vitro pollen germination. When the sucrose concentration of 30 g / L, boric acid in a concentration of 3 g / l when the Stubby cherry pollen osmotic pressure inside and outside to maintain balance, in vitro germination rate. Temperature tests showed that pollen germination and pollen tube growth rate was the highest under the conditions of 25 ° C, is not conducive to early spring cold cherry pollen germination, affecting pollination and fertilization.

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