航天诱变对山杏实生苗生长生理及解剖结构的影响OA

[Objective]This research aimed to investigate the effect of spaceflight mutagenesis on the growth and development of Armeniaca sibirica seedlings,to provide theoretical basic for A.sibirica bree-ding.[Method]This study used the seedlings of five excellent asexual lines(1,28,207,453,and 507)from five different seed sources of productive A.sibirica carried by Shenzhou Ⅻ spacecraft as materials,and con-ducted the experiment from the beginning of May(15 days after seedling emergence)to the end of Septem-ber(150 days after seedling emergence)in 2022.The seedling emergence rate was determined 15 days after seedling emergence,after which the growth traits(plant height,ground diameter,leaf length,leaf width)were measured for each seedling with an interval of 15 days.The mature leaves were collected in mid-July to determine physiological indexes(chlorophyll a,b,total chlorophyll and carotenoids content)and photo-synthetic indexes(net photosynthetic rate(Pn),transpiration rate(Tr),stomatal conductance(Gs),inter-cellular CO2(Ci)),and to observe the leaf anatomical structure change,in order to analyze the effects of spaceflight mutagenesis on the growth,photosynthetic physiology and leaf anatomical structure of A.sibir-ica seedlings.[Result]The plant height,diameter,leaf length and width of No.207 seedlings were signifi-cantly higher than those of the control by 4.62％-44.33％at 150 d.Spaceflight mutagenesis improved the photosynthetic capacity of A.sibirica,and the photosynthetic pigment content,net photosynthetic rate,and transpiration rate of the leaves of A.sibirica seedlings of various lines were improved by different degrees after spaceflight mutagenesis.Compared with the control,the leaf cells of No.507 seedling were wrinkled,showing fuzzy structure,chaotic distribution,and the thickness of each tissue was decreased after space-flight mutagenesis.But the leaf cells of No.207 seedling were plump and neatly arranged,with relatively small cell gap.The leaf thickness,the fence tissue thickness,the cellular structure tightness and the fence tissue thickness/the spongy tissue thickness of No.1 and No.28 seedlings were all significantly higher than those of the control by 9.47％-41.29％.[Conclusion]Changes in growth,physiology and leaf anatomical structure of A.sibirica after spaceflight mutagenesis,which varied among lines and in different indexes,in-dicate that spaceflight mutagenesis is an important way to improve and innovate germplasm of A.sibirica and economic forests.