Preliminary Evaluation Of Several Clones Of Castanea Mollissima In Yanshan

Castanea mollissima is an important economic forest species in China.The perennial clones(varieties)of chestnut Beilin 4,Beilin 6,Beilin 7 and Beilin 8,which grow in weijinhe forest farm of Zunhua,Hebei Province,show good cultivation characters in the growth process,but there are some differences in the growth and bearing habits,tree structure,chestnut fruit quality and other aspects of different chestnut.In this study,clones(varieties)and approved varieties of chestnut were selected as the research objects,and approved varieties of chestnut were used as the control group to analyze and evaluate clones(varieties)Beilin 4,6,7 and 8 in phenology,tree structure,fruit characters,chestnut fruit,chestnut canopy and chestnut fruit quality,so as to provide reference for variety identification and improved variety selection.The test results are as follows:The Phenophase difference between clones(varieties)and approved varieties is significant,among which the germination period and male and female inflorescence emergence period of Beilin 4 are earlier than other varieties,and the germination period and male and female inflorescence emergence period are April 14,May 19 and April 29,respectively.The blooming period of male flowers of Beilin 7was later than that of other varieties,which was June 7.The difference of tree structure between clones(varieties)and approved varieties is significant,among which the stem height and length of fruiting mother branch of Beilin 4 are larger than other varieties,and the stem height and length of fruiting mother branch are 79.67 cm and 25.96 cm respectively;the diameter of fruiting branch of Beilin 4 is smaller than other varieties,which is 0.51 mm.The East-West crown diameter and dry diameter of Beilin 6 were 288.33 cm and 24.73 cm respectively.The density of Beilin 7 was 1.44 mm,which was smaller than other varieties.The tree height,crown width,dry height and heading of Beilin 8 were lower than those of other varieties.The tree height,crown width,dry height and heading of Beilin 8 were 443.60 cm,155.00 cm,146.67 cm,56.00 cm and0.59 mm,respectively.The branching rate and bearing branch diameter of Beilin 8 were higher thanthose of other varieties,and the branching rate and bearing branch diameter were 44.18% and 0.64 cm,respectively.The difference of fruiting habit between clones(varieties)and approved varieties was significant.The fruiting coefficient,number of female flower clusters and pollen fertility of Beilin 4 were lower than those of other varieties.The fruiting coefficient,number of female flower clusters and pollen fertility were 40.63,1.24 and 74.32%,respectively.The number of male flowers of Beilin 6 was 8.42,which was more than that of other varieties;the number of fruit per bract of Beilin 6 was 2.01,which was less than that of other varieties.The last node of male inflorescence of Beilin 7 was 21.78,which was later than other varieties.The male inflorescence coarseness and pollen fertility of Beilin 8 were2.62 mm and 91.84%,respectively.The fruit shape index of Beilin 4 was 0.86,which was lower than that of the other three clones.The length of the thorn and the thickness of the bract of Beilin 6 were 7.61 mm and 2.49 mm,respectively.The diameter of spike bundle of Beilin 7 was 1.71 mm,which was larger than other varieties.The bract thickness of Beilin 8 was 2.49 mm,which was larger than other varieties.There was no significant difference in protein and starch content between clones(varieties)and approved varieties,and significant difference in water and soluble sugar content.The protein content of Beilin 4 was lower than that of the other three clones(18.72%).The water content of Beilin 6 was56.74% higher than that of the other three clones.The starch content of Beilin 7 was 43.63% higher than that of the other three clones.The soluble sugar content of Beilin 8 was 27.20% higher than that of other varieties;the soluble sugar content of Beilin 8 was higher than that of Dongling pearl at different accumulation stages;the starch content of Beilin 8 was lower than that of Dongling pearl at different accumulation stages.