Study On Adaptabiiity Of Introduction And Mechanisms Of Flower Bud Diffrentiation Of Carya Illinoensis

Pecan [Carya illinoensis(Wagenh.) K. Koch], which belongs to the Juglandaceae, is adiploid(n = 16), anemophilous, monoecious, heterodichogamous fruit species. Pecanscomprise one of the few agronomically important nut species that are nativeto North America andare endemic to the Mississippi basin.Various constituents and properties of mature pecan leaves and nuts have been analyzed, such as sterols and choline, fatty acids, amino acids, proteins, carbohydrates, trace elements(e.g., calcium, phosphorus, magnesium) and vitamins(e.g., A and B). Moreover, pecan nuts, which contain seven monoterpene hydrocarbons,are sold commercially with or without shells, inhalves, in sections of different sizes, or even as flour, and they are utilized in a wide varietyof foods, including bakery and confectionery products,desserts, ice creams, and snacks(raw, toasted, or salted).An increasing demand for pecans has resulted in a significant expansion of the number of pecangrowers both domestically and internationally, encompassing Argentina, Australia, Brazil, Egypt, Peru, South Africa, and China. Although pecan treeswere first introduced to China as early as 1890 and are prevalent in more than 20 provinces or cities, few quantitativestudies have been conducted on the growth and production performance of introduced pecans.In this study, Carya illinoensis K.Koch was used as materials to study the feasibilityand adaptabilityof introductionand to screen the varieties which were suitable for fourregions in Anhui province. On this base, daily change of photosynthesis andintercellular CO2 concentration were analyzed to provide technical support to comprehensively utilize and explore peanut germplasm. In addition, observing the cell structure of flower bud, determining the activity of POD and SOD, and Real-Time PCR for Cc LFY gene were carried on to study the mechanism of flower bud differentiation. And the results showed:1. In this study, we conducted a comparison of pecan plantation performance across four ecological locationsinvolving23 introduced cultivars over a 14 year study period. We aimed to evaluate the adaptabilityof pecan trees in Anhui Province, to quantitatively compare the traits of the 23 introduced cultivars, and to acquire preliminary cultivar adaptation data at different sites in Anhui Province.Our results indicate that the performance of the introduced pecan trees matched or even surpassed the typical performance of the native varieties. Based on regional performance, ‘Magenta csv 17-14’ is optimal for the Hefei site, ‘Elliott’ for the Hanshan site, ‘Magenta csv 17-14’ and ‘Moore’ for the Zongyang site, and ‘Sdling csv 10-5’ for the Qianshan site. This study provides validating evidence that Anhui Province is suitable for pecan introduction and that the cultivars examined are adaptable to this region.2. For Magenta csv 17-14, the variety of Carya illinoensis K.Koch, which was introducedin Hefei site, the photosynthesis rate remained was at a high level in all time except in the low temperature morning and night or high temperature noon. This results indicated more organic matter could be stored to improve production. Furthermore, daily change of intercellular CO2 concentrationwas varied regularly following the daily change of net photosynthesis rate, and kept a relative high lever in growth process.3. The differentiation of flower buds of Carya illinoensis K.Kochstarted from early April. For one plant, developing stage of flower buds in same nodal position in different branches were similar, but different in differentiation nodal position in different branches. This stagger time happened in female and male flower buds differentiation in shomoictic plant was a adaptability to cross-pollination.4. During the differentiation of flower buds, SOD enzyme activitymaintained high lever without obviously changing. While POD enzyme activity showed a single peak in differentiation process, and reached highest value during the differentiation of stamensand pistil.5.Specific expression of Cc LFY gene in female flower buds was analysed by RT-PCR in which the reference gene was Actin. In the period of femaleflower differentiation,the expression of Cc LFY gene varied significantly. From late March to early April, the expression of Cc LFY gene gradually improved, reaching the peak in April 5th. After then, the expression were low.