Study On Natural Type Partitioning And Isoenzyme Analysis Of Quercus Variabilis BL.

Q. variabilis is a kind of arbor of Fagaceae Quercus which has a widespread distribution area and is also the major regional tree of the warm temperate zone below altitude 1 600 meter in China. Through the study of Q. variabilis geographical distribution, this paper has confirmed the geographical district of researching Q. variabilis natural type; applied the theory of numerical taxology and cluster analysis method, classified the Q. variabilis of Qinba and Huanglong mountain; ascertained the standard and method of Q. variabilis plus trees selection about 30 ages in Shaanxi province different areas and selected 49 plus trees that were suitable to different areas; used isoenzyme analysis ,through the detection enzyme system of POD,GDH,EST and ADH ect, researched the genetic variation level of Q. variabilis natural populations and heredity construction of different Q. variabilis natural type .The result showed: (1) Q. variabilis distributes widely in China ,Qinba mountain is one of Q. variabilis distribution center and Huanglong mountain is the edge belt .It has a high representative to select Qinba and Huanglong mountain as the region of researching Q. variabilis. (2) The natural category of Q. variabilis may be divided into the long petiole thick bark pattern, the short petiole thick bark pattern ,the long petiole thin bark pattern and the short petiole thin bark pattern.(3) The plus trees selection of Q. variabilis should use the small sample plot method and the standard is different in each region. When we select the plus trees in Q. variabilis stand about 30a in north slope of Bashan mountain, we should make the forward selection tree as the core, set up the circle sample plot at the radius of 20m, differentiate to calculate the mD,mH,mT ratio between the minus which is the forward selection tree and the width ,highness and bark thickness of average tree and average tree. If mD 35%, mH 25% and mT 130% and this tree conforms to the standard of quantity character, then this forward selection tree is regarded as the plus tree. When we select the plus trees in Q. variabilis stand about 30a in Qinling mountain north slope, we should make the forward selection tree as the core, set up the circle sample plot at the radius of 20m, differentiate to calculate the mD,mH,mT ratio between the minus which is the forward selection tree and the width ,height and bark thickness of average tree and average tree. If mD 40%, mH 30% and mT 140% and this tree conforms to the standard of quantity character, then this forward selection tree is regarded as the plus tree. When we select the plus trees in Q. variabilis stand about 30a in Huanglongmountain, we should make the forward selection tree as the core, set up the circle sample plot at the radius of 20m, differentiate to calculate the mD,mH,mT ratio between the minus which is the forward selection tree and the width ,height and bark thickness of average tree and average tree. If mD 30%, mH 20% and mT 120% and this tree conforms to the standard of quantity character, this forward selection tree is regarded as the plus tree. (4) We have selected 49 plus trees in all which is 15 in north slope of Bashan mountain (respectively 8 in Pingli county,7 in Ningqiang county), 24 in north slope of Qinling mountain (respectively 10 in Nanwutai ,14 in Louguantai) and 10 in Huanglong mountain. (5) Q. variabilis natural population has a high variation level, proportion of polymorphic loci is 75%, allege gene average is 2.708 and the expected heterozygosis is 0.388. There is some differentiation among populations, but the most of the variation are existed in inter population and the variation only occupy 4.9% among populations.(6) The POD, MDH,EST and ADH isoenzyme spectrum type of different type Q, variabilis have a large difference. The enzyme activity of the long petiole thick bark pattern and the short petiole thick bark pattern is better than the long petiole thin bark pattern and the short petiole thin bark pattern in EST-A locus, so we may regard the strength and weakness of e...