作者机构：
[Wang, S; Wang, Sen; He, Tieding; Shao, Fengxia; Ge, Xiaoning] Cent South Univ Forestry & Technol, Coll Forestry, Key Lab Cultivat & Protect Non Wood Forest Trees, Minist Educ, Changsha 410004, Peoples R China.;[Wang, S; Wang, Sen; He, Tieding; Shao, Fengxia; Ge, Xiaoning] Belt & Rd Int Joint Res Ctr Trop Arid Nonwood Fore, Changsha 410004, Peoples R China.;[Guo, Hongyan; He, Tieding; Zhong, Wenbin; Wang, Jia; Ge, Xiaoning; Yan, Chao] Chinese Acad Forestry, Expt Ctr Subtrop Forestry, Xinyu 336600, Peoples R China.
通讯机构：
[Wang, S ] C;Cent South Univ Forestry & Technol, Coll Forestry, Key Lab Cultivat & Protect Non Wood Forest Trees, Minist Educ, Changsha 410004, Peoples R China.;Belt & Rd Int Joint Res Ctr Trop Arid Nonwood Fore, Changsha 410004, Peoples R China.
关键词：
Kadsura coccinea (Lem.) A. C. Smith;seed dormancy;seed structure;endogenous inhibitors
摘要：
Kadsura coccinea (Lem.) A. C. Smith is a significant tree species of non-timber forest. However, the low germination percentage and lengthy germination time of its seeds pose obstacles to industry development. Aiming at the problem of seed dormancy, this study first determined the seed dormancy period through seed germination test, and then comprehensively evaluated the dormancy characteristics by observing the seed coat structure, measuring endogenous inhibitors, and in vitro embryo culture. The results indicated the dormancy of K. coccinea seeds, and that the germination period was up to 80 days. Its seed coat is composed of exotesta and endotesta. The dense seed coat structure causes water absorption and air permeability obstacles to the seeds and causes mechanical restraint to the development of the embryo. Meanwhile, its seeds have substances that inhibit seed germination, and there are germination inhibitors in distilled water, methanol, petroleum ether, and ethyl acetate extracts of kernels and seed coats. The inhibitory activity of kernel petroleum ether extract was the highest, and the inhibitory activity of seed coat methanol extract was the highest. In addition, the embryo of K. coccinea developed completely and could germinate normally under in vitro conditions. This study has basically proved that the dormancy of K. coccinea seeds is caused by the seed coat (physical dormancy) and endogenous inhibitors (physiological dormancy), which provides a scientific theoretical basis to further explore the method of seed dormancy release of K. coccinea.
通讯机构：
College of Forestry, Central South University of Forestry and Technology, Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Changsha, China
摘要：
To investigate whether reproductive disorders exist in the sexual reproduction of Ziziphus jujuba Mill. 'Zhongqiusucui' and to understand the reproductive biology of 'Zhongqiusucui' and genetic improvements in jujube trees, we used 'Zhongqiusucui' flowers at different developmental stages as materials and conducted field and microscopic observations on the developmental pattern of mega- and microsporogenesis, as well as on the development of male and female gametophytes. The results show the following. 1) From the inflorescence development stage to flowering, the grade 0 bud on the inflorescence exhibited an increase in horizontal diameter, longitudinal diameter, peduncle length, and bud weight, but the rates of increase were different. From day 1 to day 5 after the inflorescence had developed, floral buds mostly grew horizontally. Day 5 was the floral bud flattening stage. From day 6 to day 8 after the inflorescence had developed, floral buds mostly grew longitudinally, and day 8 was the floral bud enlarging stage. 2) The stamens of 'Zhongqiusucui' had five anthers, and there were four locules per anther. The anther wall consisted of epidermis, endothecium, one- to two-layered middle layer, and a secretory-type tapetum. In addition, the development of the anther wall belonged to the basic type. The cytokinesis of the microsporocytes was synchronous, the tetrads mostly arranged as a tetrahedron, and the mature pollen had three germ pores, three grooves, and was bicellular pollen. During meiosis, the microsporocytes in each locule were at the same phase and therefore exhibited synchrony. Among the different anthers in the same floral bud, as well as the four locules in the same anther, the microsporocytes had asynchronous meiosis. 3) The pistils in the 'Zhongqiusucui' had two ovaries, two anatropous ovules, inner and outer integument, crassinucellate tetrads formed by the meiosis of megasporocytes aligned linearly along the nucellus, megaspore at the chalazal end that developed into the functional megaspore, which underwent mitotic division three times and developed into the mature embryo sac containing seven cells and eight nuclei, and embryo sac development of the Polygonum type. 4) The external morphology of the 'Zhongqiusucui' floral buds correlated with the internal developmental stage of the male and female gametophyte. Therefore, the internal developmental progress of the stamen and pistil can be determined by the external morphological characteristics of the floral buds.
作者机构：
[王佳; 唐艳; 王森; 洪荣艳; 陈建华; 邵凤侠] Key Lab of Cultivation and Protection for Non-Wood Forest Trees of Education Ministry, Key Lab of Non-Wood Forest Products of State Forestry Administration, Eng. Technol. Res. Ctr. of Eco-economic Forest Indust. in S. Hill and Mountainous Areas of Hunan Prov., Eng. and Technol. Res. Inst. of Jujube Indust. in S. China, Ctrl. S. Univ. of Forest. and Technol., Changsha, 410004, China
通讯机构：
[Wang, S.] K;Key Lab of Cultivation and Protection for Non-Wood Forest Trees of Education Ministry, China
关键词：
Chinese jujube;Ziziphus jujuba Mill.;Rooting of cuttings;Soluble sugars;Soluble proteins;Endogenous hormones
摘要：
‘Zhongqiusucui’ jujube secondary shoots were treated with 3-indolebutyric acid (IBA) at three concentrations, 500, 1000 and 1500 mg/L. Results show that IBA could significantly enhance rooting and root characteristics of cuttings and were best with IBA at 1500 mg/L. In the rooting process, the formation of adventitious roots was related to the consumption and accumulation of nutrients (soluble sugars and proteins) and the changes in endogenous hormones in phloem, leaf tips and leaf bases. The rooting of cuttings had a positive correlation with the consumption of soluble sugars during the period of callus formation and with the accumulation of soluble sugars during adventitious root formation and growth. Rooting was positively related to the breakdown of soluble proteins in the phloem when the callus formed, and had a positive correlation with its accumulation during adventitious root formation and growth. Leaf tips and leaf bases showed a reverse trend in changes of soluble protein. However, together with the phloem, leaf tips and leaf bases regulated and controlled the formation and development of adventitious roots. The main activities of soluble proteins exist in the leaf tips as this was the main source of soluble proteins. The relation between rooting and IAA (indole-3-acetic acid) content in phloem was positive and thus a high concentration of IAA could benefit the induction and formation of adventitious roots. However, rooting was negatively related with ABA (abscisic acid) and GA (gibberellic acid) and a high concentration of both could inhibit the induction and formation of adventitious roots. Rooting had a positive correlation with phloem IAA/ABA ratios, and higher ratios could improve rooting. Low concentrations of ZR (zeatin riboside) triggered the induction of adventitious roots, while higher concentrations promoted root growth. Endogenous hormones in leaf tips and bases had an impact on rooting. The activities of endogenous hormones mainly existed in leaf tips because they play a major role in the production and consumption of IAA and its ABA content increased during rooting. The ZR in leaf tips influenced the rooting of cuttings, especially in the callus formation and rooting stage. Leaf tips were the main source of GA.
