【摘要】 火炬松幼苗子叶数为5～10枚,幼苗子叶数与早期生长量相关性研究表明:火炬松种粒越大,子叶数越多;幼苗子叶数越多,芽苗、1年生苗木及9年生树木的生长量越大;火炬松幼苗子叶数以10枚最优,9枚优良;根据林木树高、胸径、材积的遗传增益值,早期选择的最低年龄在6～7年。该项研究说明幼苗时期子叶数多少对幼苗及今后苗木和林木的生长,都有显著的影响。火炬松播种育苗时,应选用大粒种子,并将不同子叶数的幼苗分别培育苗木,应选子叶数较多的苗木进行造林。更多还原

【Abstract】 Loblolly pine seedlings have 5-10 cotyledons.Correlation analysis between cotyledon number andearly growth reveal that:the more cotyledon number of loblolly pine seedlings,the more growth of very youngseedlings,1-year-old seedlings and 9-year-old trees.The number of 10 cotyledons is the best for loblolly pineseedlings.The number of 9 cotyledons is good also.According to forest tree height,diameter at the breastheight and volume of the genetic gain,6 to 7 years are the minimum age for early selection.The study shows thatthe numbers of cotyledons during the seedlings have a significant impact to seedlings and future growth ofseedlings and trees.In the Loblolly pine seedlings planting,We should use large seeds.The seedlings ofdifferent cotyledons should be separated in order to nurture.We should vote for those who have morecotyledons of seedlings for reforestation.更多还原