| Parashorea chinensis Wang Hsie.,also known as Optimus,grows" in China’s tropical rain forest and is China’s first and most endangered and protected plant.The current research on the genetic diversity and protection of germplasm resources of Wangtianshu needs further research.In this study,we analyzed the growth differences,physiological differences,and genetic diversity of different seedlings of Pinaceae,in order to explore the causes of the genetic variation,and to select the excellent pedigree of Tiantianshu,which can be an excellent germplasm resource.It lays the foundation for the development of protected plantation forests for excavation,improved breeding and endangered tree resources.The seedling height,ground diameter,leaf area,biomass,source hormones ABA,GA3,ZR,and IAA content,chlorophyll a,b,maximum net photosynthetic rate Pn,stomatal conductance Gs,intercellular CO2 concentration Ci,maximum transpiration photosynthesis parameters such as rate Tr,maximum primary light energy capture efficiency Fv’/Fm’,photochemical quenching coefficient qP,and non-photochemical quenching coefficient NPQ of seedlings of 15 progeny seedlings of 15 families of Wangtianshu families in Guangxi and Yunan.ISSR-PCR marker method to study polymorphic loci and effective alleles of different families in Wangtianshu Gene number,Shannon index and Nei index.The results show:(1)The coefficient of variation of the seedling height of two-year seedlings was 9.37%,and the heritability of the pedigree was 0.781,indicating that genetics had a greater degree of control over seedling height.The average height of seedlings was 20.27cm,the highest of which was Napo 03.The family had reached 23.50cm,which was 113.70%of the total average.The lowest family was Mengla 03(17.8cm),which was only 87.81%of the average;The coefficient of variation of the diameter was 11.35%and the heritability of the pedigree was 0.768.The best was the Napo 03 family.The diameter of the ground was 4.64mm,which was 117.60%of the total average.The worst family was the Mengla 03 family.The value was 3.40mm,which was 84.79%of the total average value;the coefficient of variation of leaf area was 13.84%,the heritability of family was 0.727,and the largest was the Napo 03 family,reaching 29.00cm2,which was the total average of 170.28%.The smallest was The Mengla 03 family is only 10.56cm2,which is only 62.01%of the average value.The average biomass of fresh and dry weight is the Napo 02 family with a fresh weight of 2.80g and a dry weight of 0.90g.The lowest average fresh and dry weight biomass was in the estuary 02 family,with a fresh weight of 1.65g and a dry weight of 0.26g.(2)The results of the difference in endogenous hormone content showed that the ABA content in the estuarine 03 family was the highest(54.50 ng/g)and the Maguan 01 content was the lowest(30.03 ng/g).The highest GA3 content was in Napo 03(11.59 ng/g),and the lowest in Mengla 03(3.55 ng/g).The the highest ZR content was in Napo 03(12.57 ng/g),and the family in the Mengla03 was the lowest(6.16 ng/g).The content of IAA in the Napo 03 was the highest(74.25 ng/g),while that of the Mengla 03 was the lowest(34.15 ng/g).(3)Differences in photosynthetic indicators showed that the Pn value was the highest in Napo 03(48.73μmol·m-2·s-1),the smallest in Mengla 01(23.46 μmol·m-2·s-1);the highest in Ci was Cidao 02(358.73 μmol/mol),the lowest was in Mengla 01(310.76μmol/mol);the Cond value was highest in Napo 03(0.47 mol·m-2·s-1),and the lowest in Mengla 01(310.76 μmol/mol);The value of Tr was the highest in Napo04(0.57 mmol/m2·s),and the lowest of Mengla 01(0.51 mmol/m2·s).Tianyang 01 had the highest Fv’/Fm’ value(0.27),and Maguan 02 had the lowest value(0.16);Mengla 04 had the highest qP value(0.44),and Napo 02 had the lowest value(0.15);Maguan 02 had the highest NPQ(0.83)and Napo 01 had the lowest(0.42).The content of chlorophyll a was the highest in Napo 03(0.81)and the lowest in Mengla 04(0.26).The content of chlorophyll b was the same as that of chlorophyll a.(4)There were large genetic diversities in different family lines of Rhododendron.The polymorphic loci of 15 families were in the range of 8.13%-26.85%,and the polymorphic loci of Napo 03 family were the highest,accounting for 26.85%.The lowest polymorphic locus of Mengla 03 was 8.13%.The average percentage of polymorphic loci in the family was 16.58%.The genetic differentiation analysis showed that the total genetic variation among the population accounted for 62.64%,and the variation within the population was only 37.36%.The genetic variation among provenances occupies a large proportion,and the gene flow coefficient is much less than 1,indicating that there was a clear differentiation among families.Cluster analysis tree diagram showed that 15 families were divided into five groups with different genetic distances.Among them,Napo 03 family had higher percentage of polymorphic loci,the strongest ability to adapt to the environment,and can be cultivated as a dominant species,and the Mengla 03 family had the poorest adaptability.The results of this experiment showed that the seedlings of Napo 03,Hekou 03,Napo 02 have greater growth and physiological advantages,and the Napol 03 family was the most excellent,with strong adaptability to environment and high genetic stability.However,the comprehensive indicators of the seedlings of the Mengla 03 families were poor,and their genetic stability was not high,which was not conducive to nursery cultivation.Therefore,the Napo 03 families could be selected as the most excellent family. |
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