Breeding and cultivation of High starch Potato Qingshu 2

Qingshu 2, a new high starch potato variety, was selected by Qinghai Academy of Agricultural and Forestry Sciences. The variety is a late-maturing variety with a growth period of about 120 days, good agronomic characters, strong growth potential, strong disease resistance and good quality; the starch content is 22.86%-25.83%, which is 70.10% higher than the national average of 77 varieties (15.05%), and the Vc content is 20.92mg / 100g; the taste is good, the yield level is high, the average yield per mu is 4192 kg, and the highest yield per mu is 4192 kg; it is suitable to be planted in the first cropping area of northern China.

1 Source of variety

The crop Institute of Qinghai Academy of Agricultural Sciences used Gaoyuan No. 4, which had strong disease resistance, high yield and good quality as female parent, and made sexual crossing with foreign introduced variety magura as male parent. The single plant was selected in 1992. After multi-generation selection of clones and regional and production experiments, it was propagated rapidly. The original code is 92-3-28, which is called sweet potato 328. It was approved by Qinghai crop approval Committee in 1999 and named Qingshu No. 2.

2 characteristic characteristics

2.1Plant characters: erect plant shape, luxuriant clump, strong growth potential, plant height 88 ±10.33cm, stem diameter 1.15 ±0.12cm, stem green, stem cross section triangular, stem wing straight, main stem number 2.2 ±0.42, branch number 6.1 ±0.99. the growing site is higher; the leaf color is dark green, the leaf is medium size, the margin is spreading, the compound leaf is oval, arranged moderately compact, alternate or opposite. There are five pairs of lateral leaflets, apical leaflets obtuse, secondary leaflets eight pairs, alternate or opposite, the second pair is larger, stipules falcate.

2.2 Cymes of flower and fruit characters, with 7-10 flowers, loosely arranged, flower buds oval, green purplish, total pedicel long 12~18cm, pedicel node purple, sepals green, lanceolate, Corolla light purple, diameter 3.4 ±0.2cm, petals tip, light red, stem light green. Pistil style is longer, stigma round, five-divided, green; stamens 5, cone-shaped, yellow; natural small berries round, green.

2.3 the shapes of tubers are round and oval. The epidermis is smooth, white skin, white meat, compact, no hollow; bud eyes are linear, the number of bud eyes is 7.82 ±1.22, tooth eyebrows are straight, navel is shallow, tuber is concentrated, dormancy period is long, and it is resistant to storage.

2.4Economic characters: the yield per plant is 0.88 ±0.3kg, the number of tubers per plant is 4.8 ±2.25, the weight per plant is 0.18kg, the starch content of tuber is 25.83%, the steaming taste is good; the content of vitamin C is 20.9mg/100g, the content of crude protein is 1.66%, and the content of reducing sugar is 0.6267mg/100g.

The whole growth period is about 160d, and the accumulated temperature of > 5 ℃ is 2208.4 ℃. The days from sowing to emergence were about 42 days, and the accumulated temperature of > 50C was 367.10 ℃. It was about 30 days from emergence to budding, and the accumulated temperature of > 5 ℃ was 373 ℃. The period from emergence to maturity was about 88 days, and the accumulated temperature of > 5 ℃ was 1467 ℃. The growth period is about 118 days, and the accumulated temperature of > 5 ℃ is 1841.3 ℃.

2.6 resistant plants are drought-resistant, cold-tolerant, saline-alkali tolerant, potato resistant to storage, resistant to potato mosaic and leaf roll virus, resistant to late blight, ring rot and black shank.

3 yield level

In 1992, 4000 seedlings from 32 combinations were planted in a plastic greenhouse. After observation and selection, 113 excellent individual plants were selected from the 32nd combination, accounting for 9.34% of the total number of candidates. The selected 92-3-28 single plant showed dark leaf color, strong growth potential, concentrated tuber, 7 tubers, white-skinned meat, and the yield per plant was 585g, which was the highest among the selected materials. On the basis of the selection of seedlings in the previous year, the comparison of clone varieties of the first generation in 1993 showed that the yield per mu was 2858.57kg, which was 14.34% higher than that of the control variety Qingshu 168. in 1994, the yield of the asexual second generation was 3600kg, which was 29.59% higher than that of the control variety Longshu 2. In 1995, the yield of the asexual third generation was 2235.25kg, which was 23.73% higher than that of the control variety. In the variety comparison test of the fourth generation of clones in 1996, the yield of 2604kg ranked first among all the tested varieties, which was 16.2% higher than that of the control variety Qingshu 168.

3.2 in the provincial regional test in 1997, the average yield per mu was 2213.17kg, which was 21.12% higher than that of the control variety Jiushu 202. in 1998, the average yield per mu was 2497.8kg, which was 91.34% higher than that of the control variety Jiushu 202, and ranked first among all the tested varieties.

The average yield of 3056.41kg per mu was 43.69% higher than that of the main local varieties (Xiazhai 65, Qingshu 168,Mushu 202). In the five-point test in 1997, the average yield per mu was 3036.3kg, which increased by 36.36% to 90.54% over the control variety Qingshu 168, 53.61% over Huishu 202, and 105.31% over Xiazhai 65.

4 main points of cultivation

4.1 selection of stubble Qingshu No. 2 potato has less strict requirements on the soil, except for over-acid, over-sticky, low-lying and saline-alkali soil, but the land with loose soil, fertile soil, high topography, deep soil layer and good drainage is the best. When cultivated in the field, it is not suitable to plant in the previous crops of Solanaceae and Cruciferae, in order to prevent degradation and yield reduction caused by potato diseases, so it is appropriate to choose crops such as corn, beans, rape and so on.

4.2 after the previous crop harvest, fine soil preparation should seize the opportunity to carry out autumn ploughing as soon as possible, and irrigation should be carried out in time after autumn ploughing in areas with serious spring drought to help preserve soil moisture. Organic fertilizer was applied in combination with autumn ploughing. Fine soil preparation to preserve soil moisture before spring sowing to ensure seedling emergence.

4.3 strictly selecting tubers with good seed quality as seed tubers is the material basis for increasing potato yield. Those bred by high-density seed retention technique in improved seed breeding field should be selected, which are not infected with major local virus diseases, have good storage, no rot and germination, and no mechanical trauma and cracks. Qingshu No. 2 has excellent seed character, shape and size of tubers as seed tubers.

4.4 accelerating sprouting before sowing breaks the dormancy of tubers in advance, shortens the growth period of shoots, is beneficial to early emergence, and the seedlings are strong, which is more effective than that of direct seeding. The method of sprouting: about 20 days before sowing, the seed potato was spread flat in the house with scattered light, the temperature was kept at 10: 15 ℃, and the tuber was stacked with 2-3 layers. Turn the potato pile every few days to make the germination uniform and strong. But it needs to be careful not to accelerate the bud to grow too long. When the bud grows 1~2cm, it can cut the bud and sow.

4.5 early sowing in suitable time and reasonable close planting have important effects on plant growth and development and later yield formation. The sowing date of Qingshu No. 2 is suitable when the local temperature stably passes through 5: 7 ℃. The planting density is closely related to the yield. Qingshu No. 2 is a late-maturing variety with luxuriant plants, so the density should not be too large. Generally, the row spacing is 0.7m, the plant spacing is 0.3m, and the seedling protection is 48000 per hectare.

4.6 heavy application of base fertilizer is beneficial to the root development and seedling growth of potato in the early stage. The base fertilizer is mixed with organic fertilizer and chemical fertilizer, generally applying organic fertilizer 30000~45000kg, chemical fertilizer 150kg, urea 75kg and potassium sulfate 75kg per hectare N ∶ P ∶ Kraft 2 ∶ 1 ∶ 10 can be increased or decreased according to the local fertility. When applying base fertilizer, 30kg was added to control underground pests.

4.7 the key point of strengthening field management during potato growth period is to do a good job of cultivating soil in the early stage, pay attention to waterlogging drainage and dry irrigation in the later stage, and control diseases and insect pests. From emergence to flowering, soil cultivation is generally carried out three times in a row, weeding in time after the seedlings are complete, irrigation combined with soil cultivation, and it is appropriate to keep the soil water content at 60%-80%. If there is a flood disaster during childbearing, it is necessary to drain and prevent waterlogging immediately. At the end of budding, if the plant grows excessively due to excessive water and fertilizer, it can be regulated by foliar spraying 300-10000 times or 700-1500 times. Qingshu No. 2 is more resistant to late blight, but in the case of severe disease, it should be controlled with 1000 times of 25% Trichoderma or 70% methyl thiophanate wettable powder at the initial stage of the disease.

4.8 harvested and stored in late September when the stems and leaves of the field plants were more than 90% yellow. Prevent mechanical damage. If the soil root is too wet, the harvested potato pieces should be placed in a ventilated and cool place for 1 or 2 days before entering the cellar. The heap height of potato chunks in the cellar should not exceed 1 m, and the temperature in the cellar should be stabilized at 1-4 ℃. The cellar should be turned once in the middle and late November to remove diseased potatoes and soil, and pay attention to anti-freezing, heat and humidity, so as to keep the potato pieces dormant all the time.