磷对黑木相思增殖苗丛生芽生长发育的影响

Effect of Phosphorus on Cluster Bud Growth in Proliferating Seedlings of Acacia melanoxylon

摘要:

为研究磷水平对黑木相思(Acacia melanoxylon)增殖苗丛生芽诱导及其生长发育的影响，该研究以黑木相思无性系SR17增殖苗为材料，分别接种于含0.9、1.2、1.6、2.0、2.4和2.7 mmol/L KH₂PO₄的增殖培养基，分别继代1和2个周期时调查丛生芽的生长发育指标。结果表明，2.0~2.7 mmol/L KH₂PO₄促进黑木相思增殖苗丛生芽的芽高、数量、基部愈伤组织快速生长，其中2.4 mmol/L H₂PO₄的增殖效果最佳，且丛生芽的生物量、叶绿素含量积累也相对较高；随培养基中磷水平的提高，丛生芽中磷和钾含量显著增加，氮含量无明显变化。Pearson相关性分析表明，磷水平与继代1和2周期时的芽高、数量、基部愈伤组织大小、鲜重、干重、组织含水率和总叶绿素、叶绿素a、叶绿素b、磷、钾含量呈显著或极显著正相关。因此磷对黑木相思丛生芽的生长发育具有重要调控作用。

Abstract:

To understand the effect of phosphorus on the induction and growth of cluster buds in the proliferating seedlings of Acacia melanoxylon, the tissue-cultured seedlings of clone SR17 as materials was inoculated proliferation medium containing 0.9, 1.2, 1.6, 2.0, 2.4, and 2.7 mmol/L KH₂PO₄, respectively, and the growth and development indexes of cluster buds were investigated after for 1 and 2 cycles of subgeneration, respectively. The results showed that 2.0–2.7 mmol/L KH₂PO₄ promoted the rapid growth of height, number of cluster bud and base callus of proliferating seedlings, among which 2.4 mmol/L KH₂PO₄ had the best effect, and the accumulation of biomass and chlorophyll content was higher. With the enhance of phosphorus content in the medium, phosphorus and potassium contents in the cluster buds significantly increased, while nitrogen content had no significant change. Pearson correlation analysis revealed that the phosphorus level had significantly positive correlation with height, number, base callus, fresh weight, dry weight, tissue water content, and contents of total chlorophyll, chlorophyll a, chlorophyll b, phosphorus, potassium of bud in 1 and 2 cycles of subgeneration. Therefore, phosphorus plays an essential regulatory role in the growth and development of cluster buds of A. melanoxylon.