狭瓣辣木的开花动态及花粉活力和柱头可授性

为了观测狭瓣辣木和多油辣木改良种PKM-1开花散粉时期花部形态、花粉萌发率和柱头可授性的变化规律,本研究采用琼脂培养基萌发法测定花粉萌发率,用联苯胺-过氧化氢法测定柱头可授性,结合田间花部性状随着时间变化的实际观测进行分析。结果表明,狭瓣辣木花朵开花之初,花药即完全打开并开始大量散粉,柱头直立,高于雄蕊;花朵开放后,柱头直立不变,高度逐渐低于雄蕊。PKM-1花朵开花之初,花药微微闭合,2 h后完全打开并开始大量散粉,柱头微微弯曲,高度低于雄蕊;花朵开放后,柱头逐渐弯曲,高度逐渐高于雄蕊。狭瓣辣木花粉萌发率在开花第2天达到最大值77%,呈现先上升后下降的趋势。PKM-1花粉萌发率在开花第1天达到最大值69%,之后迅速降低;狭瓣辣木和PKM-1柱头可授性均呈上升趋势,二者在开花第3天柱头可授性最强。在开花第1天,狭瓣辣木柱头具有微弱活性,而PKM-1柱头没有活性。在自然授粉条件下,狭瓣辣木花期柱头形态不利于其杂交授粉;在开花第2天采集花粉,在开花第3天柱头可授性最强时人工授粉,可以提高狭瓣辣木结实率和杂交成功率。本研究对于制定辣木杂交育种措施、提高辣木人工授粉效率和产量有重要意义。

Floral Dynamics,Pollen Viability and Stigma Receptivity of Moringa stenopetala

The variation of flower morphology,pollen germination rate and stigma receptivity during the flowering and loosening period of Moringa stenopetala and PKM-1,We determined the pollen germination rate with agar medium germination method,measured the stigma receptivity with benzidine-hydrogen peroxide method and morphological observation of stigma and pollen were adopted in the study.The results showed that at the beginning of Moringa stenopetala flowering,the anther is completely opened and begins to mass loose powder.The stigma is erect,higher than the stamen;after the flower is opened,the stigma is upright and the height is gradually lower than the stamen.At the beginning of PKM-1 flowering,the anthers were slightly closed.After 2 hours,the anthers were completely opened and a large amount of loose powder began.The stigma was slightly curved and the height was lower than the stamens.After the flowers were opened,the stigma was gradually bent and the height was gradually higher than the stamens.The pollen germination rate of Moringa stenopetala reached a maximum of 77%on the second day of flowering,showing a trend of increasing first and then decreasing.The pollen germination rate of PKM-1 reached a maximum of 69%on the first day of flowering,and then decreased rapidly.The Moringa stenopetala and PKM-1 stigma showed an upward trend,and the stigma was the most receptive on the third day of flowering.On the first day of flowering,the Moringa stenopetala stigma had weak activity,while the PKM-1 stigma was inactive.Under the condition of natural pollination,the stigma morphology of the Moringa stenopetala is not conducive to its cross-pollination.Pollen was collected on the second day of flowering,and artificial pollination was carried out on the third day of flowering when the stigma was the most receptive,which could improve the seed setting rate and hybridization success rate of Moringa stenopetala.This study is of great significance for the development of Moringa hybrid breeding measures to improve the efficiency and yield of Moringa artificial pollination.