The Influence Of Lewisia Seed Source On Plant Type And Flowering And The Construction Of Efficient Propagation System

Lewisia cotyledon B.L.Rob.is a perennial herb of the genus Lewisia in the family Amaranthaceae,with highly ornamental flowers and leaves,a long ornamental period,and a promising market.At present,the plant nursery of lewisia is mainly based on sowing,however,the high price of high-quality seeds and uneven emergence of seedlings seriously affect the production of lewisia seedlings and potted flowers.In this paper,we used seeds,leaves and suckers as the test materials to compare the survival rate,seedling morphology and flowering traits of seedlings and explore the best seedling breeding method using four methods:sowing,leaf plug,division and group culture.Different sterilization times,different hormone and concentration ratios and different culture conditions were tested using seeds and primary seedlings obtained from aseptic sowing to screen out the best culture conditions and medium formulations for each stage of tissue culture and to establish a fast breeding system for the histoculture of lewisia.The main results of the study are as follows:1.The influence of lewisia seed source on plant type and floweringThe seedlings of lewisia sowing have fast emergence,short rooting and seedling establishment time,excellent seedling growth,but low seedling emergence rate;leaf cuttings are easy to take,high survival rate,but long rooting time,long growth cycle,and limited amount of material;split seedlings have more and larger leaves,thicker leaves,thicker stalks,stronger roots,thicker flower stalks,but low reproduction coefficient;group seedlings have high survival rate,high reproduction coefficient,and more inflorescences,which are It is an effective method for factory seedling breeding.Except for leaf thickness,chlorophyll,root number and root mean diameter,which were all independent of each other and other agronomic trait variables,other agronomic traits followed the life course of total root length with the same growth trend;the 20 indicators related to the effect of different seed sources on plant size could be transformed into 2 comprehensive indicators;the 11 indicators related to the effect of different seed sources on flowering traits could be transformed into 3 comprehensive indicators.2.The establishment of efficient expansion system of lewisiaSeed sterilization and primary seedling culture:The seeds of Luvica were sterilized with 0.1%HgCl when the sterilization time was 10 min,the contamination rate was the lowest and the germination rate was the highest,80%respectively,which was the best sterilization time.The highest germination rate and effective shoot percentage were 88.89%and 100%,respectively,when the aseptic sowing growth medium was MS+1.5 mg/L 6-BA+0.2 mg/L NAA,and the growth was good.Optimization of succession culture conditions:The highest value-added multiplicity,vigorous growth,bright green leaves and translucent vitrification of a few leaves were observed when the primary seedlings were placed in DKW medium,20-25℃.Recovery of vitrification seedlings:Vitrification seedlings produced during successive proliferation were placed in DKW+5g/L PVP+2g/L activated charcoal+30g/L sucrose medium,and the highest recovery rate was 73.33%.The main order of factors affecting vitrification seedlings of lewisia was sucrose concentration>PVP>activated charcoal>basal medium.Direct induction of indeterminate shoots:Successor seedling leaves were placed in DKW+0.01 mg/L NAA+0.1 mg/L TDZ medium,and the induction rate,value-added multiplicity and proportion of effective shoots were higher,86.67%,3 and 100%,respectively,and more indeterminate shoots were induced with vigorous growth and bright green color.Somatic embryo induction:The highest somatic embryo induction rate of 77.3%was achieved by placing the leaves of sterile seedlings in DKW+0.3 mg/L TDZ medium.Root induction:Sterile seedlings produced from primary seedlings,secondary culture,direct induction of adventitious shoots and somatic embryo induction were placed in 1/2DKW+2mg/L IBA+0.4mg/L NAA medium,and the highest rooting rate was 86%.The main order of the factors affecting the rooting of Lulvicia lulvicola histoponic seedlings was sucrose concentration>IBA>NAA.