杜鹃种子形态特征与萌发特性研究

Seed Morphology and Germinating Characteristics of Rhododendron

以野生种"羊踯躅"、"映山红"与园艺品种"夏玫红"、"深球红"、"粉鹤"5个基因型杜鹃为试验材料,研究了几个种(品种)的种子形态与萌发特性,旨在为引种驯化和新品种选育提供参考依据。结果表明:5种供试杜鹃的种子均极细小,其中"羊踯躅"种子明显大于其它4种。除"映山红"与"深球红"以外,种子千粒重存在显著差异,"羊踯躅"的千粒重最重,达到0.258g;而"夏玫红"的千粒重最轻,仅为0.051g。不同杜鹃种(品种)种子形态差异显著,种子呈现椭圆形、卵形、矩圆形等形态。不同种子的翅、条纹及两端形状等均存在明显差异,可见种子形态可以作为杜鹃分类的重要依据。5种杜鹃种子萌发时滞、萌发持续时间及发芽率、发芽势、发芽指数均有差异,"羊踯躅"种子的萌发时滞最短(10d),而"映山红"最长(15d)。种子活力排序为"羊踯躅">"粉鹤">"夏玫红">"深球红">"映山红"。

Seed morphology and germinating characteristics were studied in 5genotypic Rhododendron（R.pulchrum‘Meihong＇,R.simsii,R.championiae‘Fenhe＇‘Shenqiuhong＇3cultivars and R.molle,R.simsii 2wild species）in Hubei Province,to provide reference for seedling introduction and breeding of new variety.The results showed that the seed of tested Rhododendrons were generally very small,but the seed of Rhododendron molle was significantly bigger than the others.The 1 000-seed weight of Rhododendron molle was the highest,0.258 g,while that of R.pulchrum ‘Meihong＇was the lowest,0.051 g.Seeds of different Rhododendrons were nearly ovate,elliptic,or oblong.Moreover,wing and surface striation of seed showed taxonomically useful variation in tested Rhododendrons.The germination time of R.molle was the shortest,10 days,while that of R.simsii was the longest,15 days.The germination rate（GR）,germination energy（GE）and germination index（GI）showed that R.molle〉R.championiae 〉‘Fenhe＇R.pulchrum 〉‘Meihong＇R.simsii〉‘Shenqiuhong＇〉R.simsii.