喀斯特乡土树种伊桐的种实性状及幼苗生长特征

Traits of fruit, seed and seedling growth of karst native tree species Itoa orientalis

关键词:  伊桐  果实性状  种子性状  播种萌发  幼苗生长  喀斯特  乡土树种

Key words:  Itoa orientalis  fruit trait  seed trait  sowing and germination  seedling growth  karst  native tree species

摘要:

研究了喀斯特乡土树种伊桐的果实性状、种子性状、播种萌发和幼苗生长等的基本特征。结果表明:伊桐果实单果鲜重63.20～149.50 g,其长度和宽度则分别为55.59～86.60 mm和38.59～51.80 mm,单果出种量19.95～57.15 g,出籽率31.57%～40.81%,单果种子数343～690粒,单粒种子均重0.0582～0.0857 g,其出籽率、单果种子数和单粒种子均重与果实重量存在一定程度的正相关; 伊桐种子的长、宽平均分别为(25.93±2.80)mm和(13.72±2.88)mm,完整种子平均风干重(0.0153±0.0033)g,脱翅种子平均重(0.0112±0.0024)g,种翅占整个种子的(26.56±4.53)%; 伊桐种子播前采取不同处理方式的平均发芽天数、平均发芽指数和平均发芽率等存在一定或是比较明显的差异,浸种、脱翅或两者相结合的方式均能有效缩短种子发芽时间并明显提高种子发芽率; 伊桐幼苗的株高和基径的月均生长量分别介于3.3～16.3 cm和0.32～2.80 mm之间,其中经浸种处理的前期生长较快,未经浸种处理的中期生长较快。

Abstract:

Itoa orientalis is an excellent native tree species for ecological restoration in stone desertification region. The traits of fruit,seed,sowing,germination and seedling growth of this species were studied in this paper. The results showed that single fruit of I.orientalis weighed 63.20-149.50 g. Vertical and transverse diameters of fruit were 55.59-86.60 mm and 38.59-51.80 mm respectively. Seed mass per fruit was 19.95-57.15 g and seed output was 31.57%-40.81%. Seed number per fruit was 343-690 and each fresh seed weighed 0.0582-0.0857 g. There was a positive correlation between fruit weight and seed output,seed number per fruit and single seed weight. Seed was(25.93±2.80)mm in length and(13.72±2.88)mm in width. The dry seed with wing weighed(0.0153±0.0033)g and that without wing was(0.0112±0.0024)g. Seed wing weight accounted for(26.56±4.53)% of the seed weight. The mean germination days,mean germination index and germination rate were different among different treatments before seed sown. Germination times could be shortened and germination rate could be improved by soaking seed or removing wing or by integrating this two ways. Average growth per month was 3.3-16.3 cm in plant height and 0.32-2.80 mm in stem base. Seedlings from soaking seed grew faster in prophase,while those from no soaking seed grew faster in metaphase.