牡丹远缘杂种‘和谐’育性的初步研究

Preliminary Study on Fertility of a Distant Hybrid 'Hexie' of Tree Peony

以我国选育出的首例牡丹与芍药远缘杂种‘和谐’为主要材料,对其雌雄蕊形态特征、花粉活力、授粉过程、杂交结实情况等影响其育性的关键因素和环节进行系列研究。结果表明:‘和谐’雄蕊量少,50～100枚,花丝长短不一,0.1～2.5cm;雌蕊4～5枚,花盘肉质,包裹心皮2/3左右。‘和谐’花粉多数败育,花粉活力为4.1%。牡丹和芍药混合花粉在‘和谐’柱头上萌发率很高,多数花粉管成团盘绕在柱头上,少数花粉管能进入柱头,但花粉管在花柱内因顶端膨大、胼胝质积累而停止生长,表明‘和谐’不结实是由受精前障碍造成的。‘和谐’作父本与‘艳紫’和‘粉蝴蝶’2个芍药品种杂交有一定的亲和性,并获得少量的种子和种苗,说明‘和谐’是珍贵的牡丹与芍药远缘杂交育种的亲本材料。

＇Hexie＇ is the first distant hybrid between Section Moutan and Section Paeonia bred in China.In this paper we study the hybrid reproductive biology,including morphology of reproductive organs,pollen viability,pollination and seed-set conditions.The results showed that ＇Hexie＇ flower had approximately 50 to 100 stamens,and the filaments were in various lengths from about 0.1 to 2.5 cm.There were four or five pistils,and the flower disc was succulent,and covered about two thirds of the carpel.Most of the pollens were abortive;and the vital pollen accounted for 4.1% tested by TTC.The mixed pollen grains from tree peony and herbaceous peony had a high germination rate on the stigma of ＇Hexie＇.Most of the pollen tubes stopped growing and crimping on the stigma,while only the minority could enter the stigma.Moreover,the entered pollen tube swelled at the front end and twisted in the style,and the pollen tube growth was blocked by accumulated callose.The results demonstrated that pre-fertilization barriers resulted in the infertility of ＇Hexie＇.When ＇Hexie＇ was used as male parent,crossing with herbaceous peony cultivar ＇Yanzi＇ and ＇Fen Hudie＇ showed some compatibility,from which a few seeds and seedlings were obtained,indicating that ＇Hexie＇ could be used as parent material for breeding various distant hybrids between tree peony and herbaceous peony.