摘要
【目的】以新牧4号紫花苜蓿为材料,在新疆干旱区绿洲田间试验条件下,对网室内、外开花动态、花粉活力、柱头可授性、散粉特性,以及不同近交方式结实性等进行研究,旨在揭示开花散粉规律与不同近交方式种子结实之间的关系,为苜蓿育种技术提供依据。【方法】网室内进行人工去雄控制授粉,品种内近亲交配的方式分别为同株同花、同株异花、异株异花。【结果】①新疆干旱区绿洲农田苜蓿花期网室内平均温度低于网室外,相对湿度高于网室外。②网室内苜蓿单花在早上9:00开放,网室外在早上8:30开放,单花开放高峰期网室内是12:00-16:00,网室外是12:00-15:30;单花开放后持续时间网室内为2～5 d,网室外为2～6 h。③网室内、外单花均在Ⅳ时期开始散粉,此时网室内、外的花粉活力分别是96. 33%和93. 22%;在Ⅴ时期雌蕊开裂,此时网室内、外柱头均具有较强的可授性。④品种内异株异花的结荚率为32. 14%±0. 01%、单荚种子数为(3. 57±0. 20)粒,单荚螺旋数为(3. 16±0. 10)个、种子千粒重为(2. 49±0. 02) g,比同株同花、同株异花高出1. 5～3. 0倍;网室内自然授粉的结荚率为11.67%±0. 00%、单荚种子数为(1. 63±0. 06)粒,单荚螺旋数为(1. 42±0. 06)个、种子千粒重为(1. 67±0. 12) g。【结论】在苜蓿单花发育至Ⅳ时期(旗瓣展开而翼瓣未伸出花萼)进行授粉的效率较高。在今后苜蓿纯合体系自交选育过程中,自交早世代(自交1～2代)的个体基因型杂合度高,采用同株异花交配较好;自交晚世代(3～5世代)个体基因型杂合度低,采用品种内异株异花交配较好。
【Objective】With'Medicago sativa L.cv.XinMu No.4'as the sample,floral dynamics,pollen viability,stigma receptivity,pollen dispersal characteristics and fecundity with different inbreeding patterns interior and exterior the net room were studied under the field experimental condition of arid area oasis in Xinjiang to reveal the relationship between regular pattern of blossom and pollen dispersal and seed fecundity with different inbreeding patterns,and provide technical reference for alfalfa breeding.【Method】Artificial emasculation and controlled pollination were conducted interior the net room,the inbreeding patterns within the species were hermaphroditic,geitonogamy,xenogamy.【Result】(i)The average temperature interior the net room in arid area oasis in Xinjiang during the alfalfa flower season was lower than that exterior the net-house,while the interior relative humidity was higher than that exterior the net room.(ii)Solitary alfalfa came into bloom at 9:00 am interior the net-house,8:30 am exterior the net room,solitary alfalfa blossom peak appeared at 12:00-16:00 interior the net room and at 12:00-15:30 exterior the net room;the time of duration of the solitary alfalfa blossom was 2-5 days interior the net room and 2-6 hours exterior the net room.(iii)Pollen dispersal of the solitary flowers both interior and exterior the net room started at stage IV,and the pollen viability interior and exterior the net-house was 96.33%and 92.33%respectively during that stage;Pistils split at stage V and stigmas both interior and exterior the net-house had a relatively strong receptivity during that stage.(iv)Pod setting rate of xenogamy within the species was 32.14%±0.01%,number of single pods was(3.57±0.20),helix number of single pods was(3.16±0.10),1000-seed weight was(2.49±0.02)g,which was 1.5-3.0 times higher than those of hermaphroditic,geitonogamy;Pod setting rate of open pollination was11.67%±0.00%,number of single pods was 1.63±0.06,helix number of single pods was 1.42±0.06,1000-seed weight was(1.67±0.12)g.【Conclusion】Comprehensive analysis indicated that it was the most efficient to pollinate from solitary floral development to Stage IV of alfalfa(The vexillum is fully extended and the calyx but wing is not unfolded).In homozygosis system self-cross selective breeding processing of alfalfa,the individual genotype of early selfing generations(1st-2nd selfing generations)had a higher heterozygosity,thus it was better to apply geitonogamy breeding;while the individual genotype of late selfing generations(3rd-5th generations)had a lower heterozygosity,so it was better to apply xenogamy breeding.
作者
王月异
王玉祥
金西子
张博
WANG Yue-yi;WANG Yu-xiang;JIN Xi-zi;ZHANG Bo(College of Grassland and Environmental Science, Xinjiang Agricultural University, West Arid Region Grassland Resource and Ecology Key Laboratory, Xinjiang Urumqi 830052, China)
出处
《西南农业学报》
CSCD
北大核心
2019年第1期42-48,共7页
Southwest China Journal of Agricultural Sciences
基金
公益性行业(农业)科研专项(201403048-8)
国家牧草产业技术体系岗位科学家项目(CARS-34)
关键词
紫花苜蓿
开花动态
散粉时期
近交
结实性
Alfalfa
Floral dynamics
Pollen dispersal stage
Inbreeding
Fecundity
