The features of branching and growth studied included height, diameter at breast height (DBH), total number of branches, annual height growth, annual branch elongation in the year of elongating, annual branch number f...The features of branching and growth studied included height, diameter at breast height (DBH), total number of branches, annual height growth, annual branch elongation in the year of elongating, annual branch number for four consecutive years, diameter of branches of different ages, and diameter of stem where branch-whorl originates. For features of total growth and overall branching, no significant differences were found between families, except for DBH. For annual features, no significant differences were found in annual stem height growth, annual branch elongation in the year of elongation and diameter of branches. In the last four years, differences in number of branches were not significant in the first two years but were significant in the last two year; differences in stem diameter where branch-whorls grow were significant for the four consecutive years. Trend of annual growth and branching features of families can be divided into three types as increasing type, stable type and fluctuating type. Most of families have an increasing type with respect of annual height growth and annual branch elongation, while most families belong to a fluctuating type with annual branch number. The results indicated that in the fifth year after planted in seedling seed orchard, differences between families were mostly insignificant. This result may have two main explanations: one is the growth rhyme in early ages of Masson pine, the other one is the complex paternal components to form the open-pollinated families. Family selection seemed to be not useful based on the result. It is suggested to select some of families in the nursery instead of to use all the families when establishing seedling seed orchards with open-pollinated families from plus-trees.展开更多
以湖南省城步2代马尾松种子园人工控制授粉的全同胞家系和全同胞家系的母本与父本的自由授粉半同胞家系种子为试验材料，研究马尾松2代种子园家系苗期的配合力和杂种优势。结果表明：马尾松2代种子园家系间地径、苗高的差异均达极显著...以湖南省城步2代马尾松种子园人工控制授粉的全同胞家系和全同胞家系的母本与父本的自由授粉半同胞家系种子为试验材料，研究马尾松2代种子园家系苗期的配合力和杂种优势。结果表明：马尾松2代种子园家系间地径、苗高的差异均达极显著，其中地径变幅为0．2157～0．4288 cm，苗高变幅为13．4259～35．5689 cm。全同胞家系的地径、苗高与其母本的地径、苗高均呈现正相关，其中全同胞家系地径与其母本地径的相关系为0．831，为极显著相关，其它均未达显著水平。在4个杂交组合中，2个一般配合力（GCA）较高的亲本杂交后代81×8的地径均值和特殊配合力效应值均最大，分别为0．4288 cm 和0．024；2个一般配合力较高的亲本杂交后代10×37的苗高均值和特殊配合力效应值并不是最大的，而81×8组合的苗高均值和特殊配合力效应值均是最大的，分别为35．3750 cm 和3．1934。不同组合间的杂种优势差异很大，其中地径的杂种优的变幅为－16．55％～19．41％，苗高杂种优的变幅为－46．44％～11．84％。展开更多
基金This paper was a part of the National Key Project of Science and Technology on Masson Pine breeding during 1996-2000.
文摘The features of branching and growth studied included height, diameter at breast height (DBH), total number of branches, annual height growth, annual branch elongation in the year of elongating, annual branch number for four consecutive years, diameter of branches of different ages, and diameter of stem where branch-whorl originates. For features of total growth and overall branching, no significant differences were found between families, except for DBH. For annual features, no significant differences were found in annual stem height growth, annual branch elongation in the year of elongation and diameter of branches. In the last four years, differences in number of branches were not significant in the first two years but were significant in the last two year; differences in stem diameter where branch-whorls grow were significant for the four consecutive years. Trend of annual growth and branching features of families can be divided into three types as increasing type, stable type and fluctuating type. Most of families have an increasing type with respect of annual height growth and annual branch elongation, while most families belong to a fluctuating type with annual branch number. The results indicated that in the fifth year after planted in seedling seed orchard, differences between families were mostly insignificant. This result may have two main explanations: one is the growth rhyme in early ages of Masson pine, the other one is the complex paternal components to form the open-pollinated families. Family selection seemed to be not useful based on the result. It is suggested to select some of families in the nursery instead of to use all the families when establishing seedling seed orchards with open-pollinated families from plus-trees.
文摘以湖南省城步2代马尾松种子园人工控制授粉的全同胞家系和全同胞家系的母本与父本的自由授粉半同胞家系种子为试验材料，研究马尾松2代种子园家系苗期的配合力和杂种优势。结果表明：马尾松2代种子园家系间地径、苗高的差异均达极显著，其中地径变幅为0．2157～0．4288 cm，苗高变幅为13．4259～35．5689 cm。全同胞家系的地径、苗高与其母本的地径、苗高均呈现正相关，其中全同胞家系地径与其母本地径的相关系为0．831，为极显著相关，其它均未达显著水平。在4个杂交组合中，2个一般配合力（GCA）较高的亲本杂交后代81×8的地径均值和特殊配合力效应值均最大，分别为0．4288 cm 和0．024；2个一般配合力较高的亲本杂交后代10×37的苗高均值和特殊配合力效应值并不是最大的，而81×8组合的苗高均值和特殊配合力效应值均是最大的，分别为35．3750 cm 和3．1934。不同组合间的杂种优势差异很大，其中地径的杂种优的变幅为－16．55％～19．41％，苗高杂种优的变幅为－46．44％～11．84％。
