紫花苜蓿二次航天搭载正向诱变效应研究

Study on positive variation types of alfalfa by re-onboard in space

摘要:

【目的】探索紫花苜蓿（Medicago sativa）二次航天搭载后的正向诱变效应，筛选不同变异类型的植株。【方法】通过对搭载于神舟 10 号飞船的中天 1 号紫花苜蓿的株高、叶茎比、鲜干比、多叶率、 分枝数、生物量等生产性能指标的测定，选择了 8 种正向变异类型并描述其特点。【结果】共优选多叶单株 46 株，其中 5 叶株 9 株、7 叶株 5 株，多分枝 5 株，速长 7 株，黄花 3 株、白花 4 株，抗病抗逆 9 株，早熟 4 株。研究发现紫花苜蓿二次搭载的多数变异在原始圃中发生，少数变异在后代发生，中天 1 号二次搭载后最明显的变异是多叶率的提高，且优选多叶单株的多叶率均显著（P＜0. 05）高于对照。【结论】紫花苜蓿航天诱变的变异是在品种自身主要特性的基础上发生的变异，研究者可以有目标的进行搭载和选择。

Abstract:

【Objective】 In order to explore the positive mutagenic effect of alfalfa （Medicago sativa） by reonboard in space and screen plants for different variation types.【Method】 Through the measurement of the produc- tion performance index such as plant height，leaf-stem ratio，fresh-dry ratio，multi-leaf rate，branch number and biomass of Zhongtian No. 1 alfalfa carried on Shenzhou No. 10 spacecraft，eight positive variation types were identi- fied and characterised.【Result] Forty-six multifoliolate plants including 5 leaflets （9），7 leaflets （5），multi-branch （5），rapid growth （7），yellow flower （3），white flower （4），disease-resistance and adversity-resistance （9），and early maturity （4） were selected via optimal selection. The major variations in alfalfa after its re-onboard in space occurred in primary nursery，and a few variations occurred in variant nursery. The most obvious variation after the re-onboard of Zhongtian No. 1 was the increase of leaf numbers. Rate of leaf variations of single multifoliolate plant was significantly （P＜0. 05） higher than control.【Conclusion】 The variation of alfalfa through space-flight muta- genesis techniques is the variation on the basis of the main characteristics of the plant itself. Therefore，we can select and carry out space mutation breeding in a targeted manner.