Research On Seed Development And Germination Of Gastrodia Elata

In this study,Gastrodia elata was used as the material to explore the effects of different pollen load on the fruit and seed development,and using G.elata seeds to explore the similarities and differences between the symbiotic and asymbiotic germination and the influence of different oak leaves and different media on the symbiotic germination of the seeds;observe the fruit development at different stages after pollination,and the development of flower buds,ovules and seeds.1.Effects of different pollen load on fruit and seed development.during the flowering period of G.elata,with whole pollinarium as the control group,different pollen load(cut the whole pollinarium into 1/2,1/4,1/8,1/16 respectively)on the development and setting of fruit,the fruit and seed size and weight were measured 16 days after pollination.the results show that:(1)different pollen load affected fruit size,weight and total seed weight of a single fruit;when the pollen load is 1/4 and below,the length,width and weight of the fruit(fresh and dry weight)were reduced significantly;the dry weight of seeds was about 6.0 mg with whole pollinarium and 1/2 pollinarium pollen load,and the dry weight was about 3.0 mg g and 1.6mg with 1/4 and 1/8 pollinarium;(2)different pollen load had no effect on the seed length and the size of the embryo,the length of the seed was about 0.55 cm,and the length and width of the embryo were 0.15 cm and 0.10 cm,respectively;when the pollen load was 1/4pollinarium and below,the seed width increased significantly,from 0.13 cm to 0.16 cm.2.Observation on Seed Germination of G.elata.The results show:(1)the time of symbiotic germination is shorter than asymbiotic germination,and higher the germination rate,the symbiotic germination starts at 20 days,and the germination rate after 30 days is 50%,asymbiotic germination starts at 2 months,the germination of 4 months rate is 24%;germination and seedling growth also has a large difference between the two,for example,the protocorm formed by symbiotic germination forms a slender vegetative stem without being inoculated with Armillaria,the surface of the protocorm formed by asymbiotic germination will form many growth points,and finally form a nodular rhizome through continuous bifurcation;(2)among the six leaves of Fagaceae,the germination rate of Quercus aliena was the highest,about 48%,Quercus palustrisand Fagus engleriana about 25% and 22%,respectively,the germination rate of Castanea mollissima and Quercus variabilis only about2%;(3)on three artificial media,the germination rate of seeds on 1/2MS and oat medium is82% and 63%,protocorm diameter of 1/2MS and oat medium is about 0.57 mm and 0.67 mm,the germination rate of seeds on PDA medium is 0%,respectively.3.The development process of G.elata fruit and the development of flower buds,ovules and seeds of G.elata through paraffin sections,the results showed:(1)at the end of December,the stamens of the upper flower buds of G.elata inflorescence are in the early stage of development,and the two medicine chambers are conjoined;the two chambers of the central flower bud and stamen have been split,and the sporogenous cells have divided several times,and the placenta in the ovary is raised;late April,the microspore mother cells in the stamens from the upper to the lower flower buds of inflorescence undergo meiosis to form microspores,the tapetum degenerates,the drug barrier is broken,and the bifurcated ends in the placenta of the ovary form many tiny protrusions,which develop into ovules;(2)the embryo sac has matured in early May,the mature embryo sac of G.elata has 4 nuclei and is inverted;the fertilization of G.elata is completed on the 4th day after pollination,on the 6th day after pollination,the zygote undergoes a division to form a two-cell proembryo,they are respectively involved in the construction of the stalk and embryo body,the embryo somatic cell divides several times to form the seed embryo at 8-12 days after pollination,the stalk begins to degenerate,forming a mature embryo.(3)The fruit of G.elata develops and matures on 16 days after pollination,and the fruit grows faster 1-7 days after pollination,after that,the size of the fruit has basically been finalized.