Research On After-ripening,Germination Physiology And Artificial Intervention Of Paris' Seed

The development process of embryo,rate changes of embryo,enzyme activity as well as metabolism of substances are important ways to explore the mechanism of seed germination.According to the principle of seed dormancy to select the suitable artificial intervention measures to break the seed dormancy and promote seed germination as soon as possible to provide guidance in production.In this experiment,we checked the process of embryo form,embryo rate of Paris polyphylla Smith var.chinensis(Franch.)Hara as well as the change of contents of main metabolites,such as starch,soluble sugar,protein,amino acid,crude fat.All indexes were dynamically monitored in order to explore the mechanism of germination.In germination test,we used different peeling stratification medium,different peeled method,different hormone and other medicament treatment to the seed soaking treatment in 18?stratification conditions,all indexes were observed and recorded weekly.At last,we draw a comparative analysis on differences in seed germination rate,germination energy and average germination days.The result is as follows:1.The embryonic development of Paris' seed including after ripening period(0-30d),early stage of germination(30-60d),metaphase(60-90d),anaphase(90-110d)and seedling stage(110-140d).In the ripening period,the embryo gradually developed through oval embryo,spindle shaped embryo,with complete structure of plumule,hypocotyls and radical;In the early stage of germination,embryo root elongation and break through the micropylar endosperm and the seed coat,complete the rooting stage;In medium stage of germination period,hypocotyls elongation and differentiation to the original form,namely the root hypocotyls enlargement,and the enlargement of the hypocotyls of bud primordial,fibrous roots,the epicotyls only preliminary differentiation,no elongation phenomenon;In late germination stage,hypocotyls expanded further,more fibrous root growth,endosperm degrades a lot,seed becomes soft and transparent,epicotyls differentiation and elongation in the preliminary,we can see a visible short slender epicotyls become green with light;In seedling stage,with the rapid elongation of the epicotyls,the endosperm was completely degraded,and the cotyledons developed completely green,breaking through the seed coat and be the first true leaf of seedling.2.As the main material for energy provider,soluble sugar's content decreased slowly in the after ripening period,increased first and then decreased rapidly in early stage of germination,decreased slowly in late stage of germination and then rose slightly in the late seedling stage;starch content increased slowly after ripening period,and then decreased rapidly in the early stage embryo,in radical elongation to differentiation stage(middle and late),the content remained stable and then significantly increased in seedling stage;The soluble protein content was slightly increased and then decreased rapidly in the after ripening period and early stage of germination,which continues to decrease in the late germination stage,after what increased rapidly in seedling stage;The content of amino acid showed increased rapidly and then decreased rapidly in the embryo's after ripening period,early stage of germination,medium stage of germination as well as late stage of germination,but its continued low level in seedling stage;The content of crude fat in the embryo's increased rapidly in after-ripening period and then decreased rapidly in the early stage of germination,then increased gradually in late stage of germination and stay stable in seedling period.In stratification process,the contents of Paris' seeds was continuous changed during germination process,and with the promotion of the mutual transformation,it is a complex physiological and biochemical process.3.In seed after ripening and germination process of Paris'seed,the antioxidant level in the seed germination stage and seedling stage showed increased,while other stages decreased.SOD and CAT's activity has a similar trend:enzyme activity increased in the early stage of germination as well as seed ripening period,while decreased and was later reduced to the minimum in middle and later stage of germination,after then the activity rebound in the seedling stage;POD's activity increased in the embryo after ripening period and declined gradually in early and medium stage of germination,and increased rapidly in late stage of germination,after then remained stable in the seedling stage;The activity of a-amylase in the seeds increased slightly in embryo's after ripening period,but decreased rapidly in the early stage of germination,then gradually increased in the middle and late stage of germination and seedling stage;MDH's activity increased slowly in the embryo's after ripening period and early stage of germination,shows respiratory metabolism activity increased gradually in laminated seed,and then declined dramatically in 60th day of laminated stage,and later then the product were kept at a low level in medium and late stage of germination;G-6-PDH's activity increased rapidly in seed embryo's after ripening period,and remained at a high level in the early and middle stage of germination,and then decreased gradually in the later stage of germination.The activity changes of MDH and G-6-PDH in seed after ripening stage as well as early stage of germinations shows modes of Glucose metabolism,and was also associated with embryonic development process.4.The testat can inhibit the germination of the seed of Paris.Compared with unpeeled seeds,frozen peeled treatment can shorten the germination time significantly,and seeds peeled by rubbing sand,gauze,hand stripping shows lower germination rate and germination potential significantly;Compared with the loam matrix,seeds stratificated with fine sand,vermiculite and sawdust shows higher seed germination rate and germination potential significantly,and seeds with vermiculite can significantly shorten the germination time;Treatment with IAA,6-BA,GA3 can enhance seed germination rate,germination energy and shorten the average germination days significantly,with the best concentration of 1 mg/L.Treatment with NaN3,H2O2 and KN03 can enhance seed germination rate significantly,but the germination energy and average germination days of NaN3 and KNO3 seem to be not satisfactory.Paris' seeds should be soaked with 0.001%H2O2 for germination in production.