Optimization of in vitro adventitious root induction contributes to the development of a large-scale production system of hybrid clone seedlings of larch(Larix spp.).We used orthogonal testing to investigate the facto...Optimization of in vitro adventitious root induction contributes to the development of a large-scale production system of hybrid clone seedlings of larch(Larix spp.).We used orthogonal testing to investigate the factors that affect the rooting of hybrid larch shoots-activated carbon,vitamin B1,sucrose,glycine,glutamic acid(Glu),cysteine,pH,and induction time in the dark and indole-3-butyric acid(IBA).Variance analysis showed that the effects of sucrose concentration on rooting rate,survival rate,and average root number,pH on the average number of roots;and Glu on survival rate were all significant(p<0.05)when compared to the mock treatments.Among all of the 45 treatments,the highest rooting rate was 90%,the highest survival rate was 100%,and the highest average root number was 11.8.The theoretically optimal procedure of in vitro root induction of hybrid larch shoots is shoot induction on L9 modified medium(pH 6.7)containing 2 mg.L^(-1)naphthalene acetic acid,0.25 mg.L^(-1)IBA,1/3 macroelements,7.5 g.L^(-1)sucrose,and 5 mg.L^(-1)Glu for 8 days,and then root induction on L9 modified medium without auxin.展开更多
Five 5.5-year-old hybrid families seedling ortets in larch nursery of Maojingba forest farm,Hebei Province,were used as regenerating materials in this experiment,the effect of IBA concentration and soaking time on roo...Five 5.5-year-old hybrid families seedling ortets in larch nursery of Maojingba forest farm,Hebei Province,were used as regenerating materials in this experiment,the effect of IBA concentration and soaking time on rooting of semi-hardwood cuttings of hybrid larch and the response of different hybrid families to auxin treatment were systematically studied,and the genetic parameters of rooting under different auxin treatments were estimated. The results showed that suitable IBA treatment had an obvious effect on accelerating rooting and root development of hybrid larch cuttings. Rooting percentage increased with enhancing IBA concentration or extending soaking time,but decreased when reaching a certain concentration and soaking time. The root number increased with enhancing IBA concentration or extending soaking time,however,one-sided rooting percentage had reverse trend. Rooting percentage and root development of Larix kaempferi 73-2×Hybrid 93-16 were better than other hybrid families,the percentage of rooted cutting was up to 94% and mean root number per cutting was 5.3 by 200 mg·L-1 IBA soaked with 20 min. The following hybrid family was L. kaempferi 12 ×L.gmelinii 9,whose percentage of rooted cutting was up to 87% and mean root number per cutting was 4.8 by 400 mg·L-1 IBA soaked with 30 min. Genetic parameters of rooting traits changed greatly under the different auxin treatments,the trend of changes in the heritability of root number and rooting percentage with the IBA concentration and soaking time was similar to the root number and rooting percentage by the different auxin treatments.展开更多
基金This research was funded by The National Key Research and Development Program of China(Project No.2017YFD0600401).
文摘Optimization of in vitro adventitious root induction contributes to the development of a large-scale production system of hybrid clone seedlings of larch(Larix spp.).We used orthogonal testing to investigate the factors that affect the rooting of hybrid larch shoots-activated carbon,vitamin B1,sucrose,glycine,glutamic acid(Glu),cysteine,pH,and induction time in the dark and indole-3-butyric acid(IBA).Variance analysis showed that the effects of sucrose concentration on rooting rate,survival rate,and average root number,pH on the average number of roots;and Glu on survival rate were all significant(p<0.05)when compared to the mock treatments.Among all of the 45 treatments,the highest rooting rate was 90%,the highest survival rate was 100%,and the highest average root number was 11.8.The theoretically optimal procedure of in vitro root induction of hybrid larch shoots is shoot induction on L9 modified medium(pH 6.7)containing 2 mg.L^(-1)naphthalene acetic acid,0.25 mg.L^(-1)IBA,1/3 macroelements,7.5 g.L^(-1)sucrose,and 5 mg.L^(-1)Glu for 8 days,and then root induction on L9 modified medium without auxin.
文摘Five 5.5-year-old hybrid families seedling ortets in larch nursery of Maojingba forest farm,Hebei Province,were used as regenerating materials in this experiment,the effect of IBA concentration and soaking time on rooting of semi-hardwood cuttings of hybrid larch and the response of different hybrid families to auxin treatment were systematically studied,and the genetic parameters of rooting under different auxin treatments were estimated. The results showed that suitable IBA treatment had an obvious effect on accelerating rooting and root development of hybrid larch cuttings. Rooting percentage increased with enhancing IBA concentration or extending soaking time,but decreased when reaching a certain concentration and soaking time. The root number increased with enhancing IBA concentration or extending soaking time,however,one-sided rooting percentage had reverse trend. Rooting percentage and root development of Larix kaempferi 73-2×Hybrid 93-16 were better than other hybrid families,the percentage of rooted cutting was up to 94% and mean root number per cutting was 5.3 by 200 mg·L-1 IBA soaked with 20 min. The following hybrid family was L. kaempferi 12 ×L.gmelinii 9,whose percentage of rooted cutting was up to 87% and mean root number per cutting was 4.8 by 400 mg·L-1 IBA soaked with 30 min. Genetic parameters of rooting traits changed greatly under the different auxin treatments,the trend of changes in the heritability of root number and rooting percentage with the IBA concentration and soaking time was similar to the root number and rooting percentage by the different auxin treatments.
