Seedling grafting and breeding techniques of improved varieties of Green Crispy Plum

Seedling grafting and breeding techniques of improved varieties of Green Crispy Plum

Green crisp plum belongs to the drupe fruit of Rosaceae, which is one of the traditional fruit varieties in China. The average single fruit weighs 40 g, the fruit is slightly flat and round in shape, the top of the fruit is flat, and the apex is slightly concave; the pericarp is yellowish green, thin, covered with white fruit powder, smooth, yellowish flesh, dark coloring near the core, sweet and juicy, dense meat, crisp and refreshing. 1 the fruit is nutritious and contains sugar, acid, protein, vitamins and minerals.

It has high commodity and nutritional value and is deeply loved by consumers. Green crisp plum is a representative high-quality summer fruit variety in Xuanhan County, which comes to market in the off-season, with typical local characteristics and advantages, strong stress resistance, high yield, obvious benefit and rich resources. In the past, the root tillering method or cutting method was often used to propagate and plant, but the survival rate was not high, and the excellent characters and fruit quality varied greatly. In order to give full play to the advantages of local characteristic varieties in Xuanhan County, cultivate and strengthen the green crisp plum industry, better create the characteristic green crisp plum industry brand, make the green crisp plum industry develop in the direction of standardization and scale, and explore the seedling breeding technology of green crisp plum varieties, in order to solve the problems of mixed varieties and poor quality of green crisp plums.

1 Garden site selection

The sandy soil with convenient transportation, leeward to the sun, fertile and loose soil, pH 5.2-7.0, good drainage and irrigation is selected as the seedling land, and the groundwater level of the land is less than 1 m and there is no pollution source.

2. Land preparation

Remove weeds and debris from the nursery and turn more than 25 to 30 cm. Before soil preparation, urea 8 kg and mature farm manure 2000 kg were applied every 667m. After mixing them with fine soil, they were evenly scattered on the nursery, then ploughed and raked flat. The ground is broken, loose and flat, with a height of 0.1 m, a width of 1.2 m and a ditch width of 0.3 m, which is easy to manage.

(3) cultivate rootstock seedlings

3.1 sowing

In December of that year, the seeds of hairy peach with good germplasm were selected and disinfected in 0.5%KmnO4 for 1 h before sowing, then soaked in clean water for 24 h to accelerate germination. Remove and drain the water, open a ditch on the border and sow it at a depth of 4-5 cm. Mix the seeds with the soil, flatten them, and pour enough water. The sowing rate is generally 200 kg/667 m. After sowing, the seedling bed is covered with agricultural film and covered with a small arch. The soil should be kept moist before the seedlings are unearthed, and the surface soil should not be whitened.

3.2 Seedling arrangement

In late March of the following year, the height of peach seedlings was about 0.1m and 0.15m, which could be arranged and planted. Make a seedling bed before transplanting. The height of the bed is 0.1m-0.2m, the width of the bed is 1.2m, the width of the furrow is 0.3m, the length depends on the topography, generally no more than 30m. Generally, the north-south direction is adopted, and the mountain area is not suitable to be used as a bed along the slope, with a plant spacing of 3 cm and a row spacing of 0.2 m and 0.3 m. The seedling bed needs to be irrigated once before seedling and immediately after planting. Transplanting should be carried out on cloudy days or after rain, and should not be planted when the soil is too wet. When planting, let the seedling roots stretch, compact the soil, and closely combine the soil with the roots.

3.3 Seedling stage management

After the seedlings are cut, the strong seedlings of rootstocks are cultivated in strict accordance with the seedling management technology of "diligence, replenishment, chasing, prevention and picking". Diligent fertilization: after planting, after the seedlings survive and take root, clear fecal water is applied once a month, and 4 times of fertilization is carried out by sprinkling or spraying on rainy days. The main application is urea, 1.5-2.5 kg per 667m, and the concentration of urea is 0.3%-0.4%, potassium dihydrogen phosphate 0.3%-0.5%. Supplementary fertilization is applied to weak and fine seedlings with poor growth to promote their rapid growth. Topdressing: topdressing once before grafting to ensure that rootstocks can provide sufficient nutrients for budding after grafting; prevention of diseases and insect pests: timely control of peach seedling aphids, powdery mildew and other field diseases and insect pests with carbendazim and other pesticides, coring: coring peach seedlings in time in the middle of May to promote thick and strong seedlings, until the middle of June, the average diameter of rootstocks reached more than 3 mm to meet the grafting specifications. In addition, it is necessary to weed and loosen the soil in time, and irrigate in time during drought to ensure that the seedlings thrive.

4 grafting

4.1 choose the scion

In order to ensure the quality of green crisp plum seedlings, scion varieties should be strictly controlled. The scion of the variety used for grafting is a selected green crisp plum variety with high yield, high quality and strong stress resistance. In the middle and upper part of the periphery of the crown of adult trees, the sturdy branches with lignified, full tissue, full bud eyes and free of diseases and insect pests were collected. The leaves of the harvested scion should be removed in time, a section of petiole should be retained, bundled, and the lower end should be inserted into clean water for preservation. Immediately after scion selection and harvest, it is wrapped, stored, transported and kept with wet cloth to ensure the freshness of ear strips, which is conducive to the survival of grafting. The scion grafted in spring, generally combined with winter shearing, was cut into 20-30 cm long and bundled into 1 bundle per lOO root, wrapped with film and placed in a low-temperature cellar, freezer or trench sand storage. First cushion 1 layer of wet river sand, the thickness is 5: 10 cm, spread the scion flat 1 layer, and then add river sand, the thickness of no scion is appropriate. In this way, one layer of river sand and one layer of scion should be covered with 7-10 cm thick river sand, and the total number of layers of scion is generally no more than 3 layers. No matter what kind of storage method is used, the scion should be checked for dehydration and mildew at any time. Rootstocks are required to be robust and erect, with well-developed fibrous roots, more than 40 cm high and more than 0.3 cm in diameter of root neck.

4.2 keep a good graft

The grafting of QingCan Li Fuji is the first time in Xuanhan County, and it has basically achieved the goal of "sowing in that year, planting in that year, grafting in that year, and coming out of the nursery in that year". It shortens the seedling raising cycle, reduces the seedling raising cost, and breaks the traditional seedling raising mode of sowing and breeding rootstocks in the first year and grafting in the following year. In the method of grafting, the method of "single bud ventral grafting" was adopted. Disinfect the grafting tool with 75% alcohol before grafting and use a blade 45 at 2 / 3 clrl above the ground. Angle from top to bottom oblique cut 1 knife, deep to the xylem, see the bone does not hurt wood. The incisor is about 1.5 cm long, and the incisor skin is cut off from the scion, so that the embedded bud I is obliquely cut at the corresponding part of the scion, the cut is smooth, and the cut length is the same as that of the rootstock. The scion incision is embedded into the cut of the rootstock stem, and the cambium on one side of the rootstock is aligned, so that the interface between the two sides is closely bonded to promote the wound healing as soon as possible-tie the rootstock and scion tightly with 0.06 mm plastic film Prevent the joint from being ventilated or infiltrated into Rain Water, reduce the occurrence of diseases such as glue disease in the future, and ensure the survival of grafting.

5Seedling management after grafting.

5.1 check the survival rate

The grafting time is chosen on a sunny and windless day, and careful management after grafting is the key to the survival of grafted seedlings. About 10 days after that, the survival rate was identified in time, the color of the surviving buds was fresh as usual, and the buds that had withered or obviously died were removed and repaired in time.

5.2 cutting anvil to remove germination and promote sprouting

After survival, the part of the rootstock above the bud was cut off three times, and the sprouting on the rootstock was wiped out in time. Although the growing points of rootstock seedlings have been removed during grafting, the new buds sprout and grow rapidly, often compete with scions for nutrients, affecting the survival of grafted seedlings. Therefore, these sprouts should be removed at any time, usually once every 7 to 10 days. When the grafted buds survive and germinate, the rootstock should be cut in time to concentrate nutrients to promote budding. Operate lightly so as not to damage the newly germinated buds of the scion or loose the scion.

5.3 strengthen field management

The grafted green crisp plum seedlings are weeded once every semimonthly, combined with loosening the soil and applying fertilizer and water frequently, and irrigation and drainage should be carried out in time in case of drought and waterlogging. The main fertilizer is human and animal fecal water, every 100 kg fecal water + urea 0.5 1kg, not less than once a month. For seedlings that do not grow upright, when the seedlings grow to 30 cm, they should stand up and straighten up. Timely prevention and control of diseases and pests, and pay attention to the control of diseases and insect pests such as blight, peach stripe and wheat moth, so as to make the grafted seedlings grow rapidly and healthily.

6 colonization

It is suitable to plant in the same year after the seedling leaves fall off each year and before sprouting in the following year. The soil layer of the planted orchard is deep, the texture is good, the soil is loose and fertile, and the drainage and irrigation is good. It is suitable to take the sandy loam soil, but the land where the stone fruit trees such as peach and apricot have been planted is not suitable for planting. The row spacing is generally 3 m × 4 m, and 55 trees are planted every 667 m.