Research On Key Techniques For Rapid Propagation Of Walnut Seedlings

In order to establish the rapid propagation system of walnut seedlings，walnut seedsand ’ Lv Ling ’ walnut shoots were used as experimental material which were obtainedfrom Shexian County and5year-old scion nursery of Hebei Lvling Fruits CO. LTD inorder to study the walnut rootstock seedlings cultivation system and walnut graftingseedling cultivation system, The rapid propagation technology system of walnut seedlingswas established by plant growth regulators treatment, protected cultivation methods,sowing time and grafting time. The main results are as follows:1. IAA and6-BA solution immersed the walnut seeds inhibited its germination; lowconcentration of GA₃solution was benefited to seed germination, and high concentrationof GA₃inhibited seed germination, the emergence ratio of walnut planted in small archshed treated by50μ g/L GA₃solution was the highest,which was up to73.00%, and6.60%higher than the control; low concentration of NAA solution was benefited to seedgermination, and high concentration of NAA inhibited seed germination, the emergenceratio of walnut planted in small arch shed treated by20μ g/L NAA solution was thehighest,which was up to72.73%, and6.33%higher than the control.2. The germination rates of walnut sowed in spring and autumn were66.40%and56.92%respectively, the germination rate of walnut sowed in spring was significant higherthan that of sowed in autumn. The walnut rootstock seedlings height and the grounddiameter sowed in autumn were significant higher than that of sowed in spring. Theseedlings height and the ground diameter of walnut sowed in autumn were39.42cm,1.14cm in July1st, and the seedlings height and ground diameter sowed in spring were28.14cm,0.79cm, that the height and the ground diameter of autumn sowing rootstockseedling were40.09%and44.30%higher than that of spring sowing rootstock seeding.3. The germination rate and seedlings growth were enhanced significantly by smallarch shed covered. The germination rates of walnut sowed in autumn covered by smallarch shed and plastic film were56.92%and49.96%respectively, and they were verysignificant higher than that of contro（l40.63%）,and the germination rate of walnut coveredby small arch shed was significant higher than that of covered by plastic film; Theseedlings heights sowed in autumn covered by small arch shed and plastic film were13.16cm,10.87cm respectively, and they were very significant higher than that of control （7.91cm）, and the height of walnut covered by small arch shed was significant higherthan that of covered by plastic film.4. Soaking treatment had no significant effects on the germination and seedlinggrowth of walnut.5. There existed very significant positive correlation between the rootstock seedlingsground diameter and the grafting survival rate in June10th, July1st and August1st, thecorrelation coefficients were0.874,0.977and0.92respectively; There existed verysignificant positive correlation between the rootstock seedlings ground diameter and thegrafted seedlings height in June10th, July1st and August1st, the correlation coefficientswere0.925,0.713and0.939respectively.6. The grafted survival rate of walnut seedlings was increased with the grounddiameter, the survival rate of grafting decreased from June10th. Among the three periodof the selected test, the highest survival rate was grafted on June10th among all the grounddiameter class, and the lowest survival rate was grafted on August1st. The mostappropriate square budding period was in June, the second was in July, and August was notsuitable.7. In August, the best grafting was bud grafting with xylem. the survival rate reached33.33%, and it was significant higher than that of square budding, abdominal cut graftingand shoots cleft grafting.8. Walnut seed sowed in autumn, covered by small arch shed, the annual seedlingswere grafted with square budding in July1st, grade one and grade two seedlings （threewhen seedlings） account for65.66%of the total; all of the grafted seedlings of springsowing walnut were below to20cm, not up to standard out of nursery...