Study On Variation Of Filial Generation Of 23 Relict Plants Of Metasequoia Glyptostroboides

Metasequoia glyptostroboides Hu et Cheng, a kind of plant belong to Metasequoia, is arare relict plant in the world and specialties in China. Discovery of natural Metasequoiaglyptostroboides forest in China in1940s was regarded as an important discovery in biologyfield and recognized as "the living fossil plants".Metasequoia glyptostroboides is a fine tree species for afforesting and virescence, withthe characteristics of fast growing, wild wider suitable area, easy-planting,rapid yield andgood shape etc. It has been acclimated and domesticed widely in the world now. MostMetasequoia glyptostroboides forests cultivated all the world origined from filial generationsof mother trees of LiChuan HuBei province. It was of good significance for studying variationbetween relict mother trees families and selecting good families to build Metasequoiaglyptostroboides seed orchards and cultivate seedlings with fine multi-characters.The study sampled and collected some cones and seeds from 23 Metasequoiaglyptostroboides mother trees randomly in LiChuan HuBei province. 23 families seedlingswere obtained from its seeds. Then the 23 families seedlings were adopted as our researchmaterial. Weights of per 1000 seeds, seeds germination rates and the percentage of liftedseedlings were studied as well as heights and ground diameters of the one-year old, two-yearold and three-year old seedlings. Crown sizes and number of branches of the three-year oldseedling also were been studied. The aim of the study was to find out varivance between relictmother trees families, select good families and analyse some genetic parameters, such asheritability and genetic gain etc.Major research results were as follows:1. It had obvious differences between weights of per 1000 seeds, seeds germinationrates and the number of lifted seedlings from per cone's seeds of the 23 Metasequoiaglyptostroboides individuals. The max weights of per 1000 seeds (family 27) was 2.02 timesof the minimum(family 41); The max seeds germination rates (family 25) was 18.44 timesof the minimum (family 24); The max number of lifted seedlings (family 27) was 21.67times of the minimum (family 34).2. It had little difference between height and ground diameters of one-year oldseedlings of the 23 Metasequoia glyptostroboides families. The max height (family 28, 1) was2.68 times of the minimum (family 46); The max ground diameter (family 30) was 1.43times of the minimum (family 46). Whereas it had extremely significant differencesbetween height and ground diameters of two-year old, three-year old seedlings of the 23Metasequoia glyptostroboides families. As for two-year old seedling, the max height (family28) was 2.22 times of the minimum (family 46); the max ground diameter (family 30) was 1.6 times of the minimum (family 46). As for three-year old seedling, the max height(family 30) was 1.83 times of the minimum (family 46); the max ground diameter (family30,29) was 1.55 times of the minimum (family 15).3. Variance of height and ground diameter between the 23 different families is higherthan same family. It have obvious differences between height and ground diameter of the 23families. The max height variance (family 1) is 4.78 times of the minimum (family 31);the max ground diameter variance (family 41) is 5 times of the minimum (family 46). Andheight variance are higher than ground diameter variance in most families.4. Heritabilities of height and ground diameter in the second year and the third yearwere different and both high. But the heritabilities of height and ground diameter in thesecond year both higher than the third year, showing the heritabilities becoming lower andlower. According the results of multiple comparison, family 46 and family 15 were eliminated,and then genetic gain of height and ground diameter were 2.21% and 1.5% respectively.Genetic gain of height was higher than ground diameter.5. It had little difference between crown sizes and number of branches of the three-yearold seedlings. The max crown size (family 6) was 1.53 times of the minimum (family 1);the max number of branches (family 6, 8) was 2.47 times of the minimum (family 1).6. Correlation coefficients between weights of per 1000 seeds and growth of height andground diameter both were low and had unsignificant differences. It showed that weights ofper 1000 seeds had little influence on growth of height and ground diameter. The growth inheight and grotmd diameter in the earlier years had significant or extremely significant effectson its growth in later years, which decreased with span of time. The Correlation coefficientsbetween height and ground diameter in every same year were high, and up to extremelysignificant differences.7. The results of cluster analysis showed that among the 23 families tested, family 30,29, and 28 exhibited excellent characters all the time, which were regard as the ones with bestpotential; whereas family 46, 15 exhibited inferior characters all the time, which can beeliminated in following selection. Group 4 and 5 of Guihua village were regarded as excellentresources districts judged by the selected excellent families. Relationship between relictmother trees of Moudao 00001 of Lichuan Hubei, Shuangmiao village of Xinguo county,Group 4, 5, 9 of Hongsha village and Group 17 of Guihua village were closer. Whereasrelationship between relict mother trees of Group 4, 5 of Hongsha village and Group 4, 5, 7, 9of Guihua village were closer.