烤烟苗期营养特性的基因型差异及其杂种优势分析

Genotype difference and heterosis of nutrient characteristics of flue-cured tobacco in seedling stage

试验选用6个杂交烤烟组合共13种基因型,研究了苗期营养特性的差异,并分析F1代烟苗营养特性与亲本之间的相关性和杂种优势。结果表明:1)不同基因型烟苗的生物量、根冠比、养分(氮、磷、钾)含量和吸收量、硝酸还原酶活性、叶绿素含量、根系活力差异显著,表现出多样性;2)在F1代烟苗中,根系氮、磷、钾和地上部氮、钾含量,以及干物质积累量、根系活力和根冠比与父本和母本值之间相关性不显著,地上部磷含量与中亲值之间呈显著负相关,叶片硝酸还原酶活性与母本值之间呈显著正相关,叶绿素含量与父本值、中亲值和低亲值之间呈极显著正相关;3)烟苗根系磷、钾含量、地上部氮含量、硝酸还原酶活性、叶绿素含量、根系活力、根冠比、干物质积累量具有一定的中亲优势。根系磷含量、硝酸还原酶活性、根系活力、根冠比和干物质积累量具有超高亲优势。尽管根系氮含量和地上部磷、钾含量无明显杂种优势,但有的试验组合也表现出中亲优势和超高亲优势。

Six hybrids and 13 genotypes of flue-cured tobacco were used to study the genotype difference, parent- offspring correlation and heterosis of F1 generation in their nutrient characteristics. The results showed a significant difference in biomass, root/shoot ratio, contents and absorptions of nitrogen （N）, phosphorus （P） and potassium （ K）, chlorophyll concentration, nitrate reductase （NR） activity and root activity among different genotypes of flue- cured tobaccos in seedling stage. The contents of N, P and K in roots and N and K in shoot, dry matter accumulation, root activity and root/shoot ratio showed no significant correlations between F1 generation and the parents. There was a significant negative correlation between P content in shoots of F1 generation and mid-parent, while NR activity of F1 generation had significant positive correlation with female parent. The chlorophyU concentration of F1 generation correlated significantly with male parent, mid-parent and low-parent. The P and K contents in root, N content in shoot, NR activity, chlorophyll concentration, root activity, root/shoot ratio, dry matter accumulation of flue-cured tobacco in seedling stage had mid-parent heterosis. The P content in root, NR activity, root activity, root/shoot ratio, dry matter accumulation had over high-parent heterosis. The N content in root and P, K contents in shoots had no significant heterosis, but some cross combinations had mid-parent heterosisand over high-parent heterosis.