Research Progress on Introduction and Cultivation Techniques of Philippine Oil Fruit

Research progress on introduction and cultivation techniques of phenanthrene avocado

Fund project Huzhou City, Zhejiang Province, Public Welfare Technology Research key Project (2015C112027).

Philippine avocado is a perennial woody plant of Myrtle family, which has other names such as Fei Yue fruit, Feiji fruit, pineapple guava, pineapple guava, Brazilian guava and so on. Philippine avocado is a small evergreen tree with a plant height of 2 ~ 3 m. It is native to Brazil and Uruguay. Its artificial cultivation began in 1887 and was introduced to Switzerland, France, the United States, Italy, New Zealand and other countries. With the large-scale introduction and cultivation, improved variety selection and commercial cultivation abroad, the fruit quality of Philippine oil fruit has also increased from less than 50 g to 260 g. As a new fruit, it has appeared in New Zealand, Australia and other foreign markets. In recent years, the introduction and cultivation of Philippine avocado has been carried out in some areas of our country, but because the domestic research and application of Philippine avocado is still in its infancy, the seedlings are mainly obtained by import, there is a great gap in the market, and the supply of seedlings is in short supply. as a result, the popularization of Philippine avocado in China is limited. The research progress of introduction and cultivation techniques of phenanthrene avocado was reviewed in order to provide reference for the development and utilization of phenanthrene avocado.

1 present situation of introduction and cultivation and prospect of development and utilization of phenanthrene oil fruit in China

At present, the main introduction areas of Philippine avocado in China are Zhejiang Province, Jiangsu Province, Sichuan Province, Hunan Province, Tianjin, Shanghai and so on. The introduced varieties of phenanthrene avocado are mainly

There are Anatoki, Kakariki, Barton, Coolidge, Mammoth, Unique, Apollo, Gemini, Triumph and so on, including early, middle and late maturing varieties. Philippine oil fruit has strong adaptability, like light, cold, drought, heat, salt and waterlogging, so it is suitable for planting in South and Southwest China.

Phenanthrene avocado is an evergreen tree species of the four seasons, the leaves can absorb dust and purify the air, and the leaves are rich in phenols, flavonoids, VC, strong antioxidant capacity, can be used to develop natural antioxidants, anti-tumor drugs, anti-inflammatory drugs and health products]; the branches are resistant to pruning, and will emit a fresh smell after pruning, which can be used as flower beds, hedges, courtyard greening, potted plants, landscape tree species, etc., to enrich the species of green trees. Its bright color, pleasant fragrance of flowers, easy to attract bees, butterflies, ants and other insects, convenient pollination, flowers for viewing, and rich in anthocyanins, with a variety of health care functions, not only can be eaten directly, but also can develop health products and medicines; the fruit is sweet and delicious, with a mixed aroma of pineapple and strawberries, often attracting birds and insects to eat, and convenient fruit harvest. The content of iodine compound in fresh fruit is 1.65 ~ 3.90 mg / kg, which is the first of all fruits, so it is called "wisdom fruit". Fresh fruit contains VC 280 ~ 350 mg / kg, sugar 100 ~ 160g / kg, organic acid 3 ~ 14g / kg, protein 9 g / kg, fat 2 g / kg, potassium 1660 mg / kg, sodium 50 mg / kg, calcium 40 mg / kg, magnesium 80mg / kg, phosphorus 100 mg / kg, iron 0.5 mg / kg. It has high nutritional value and can be used to develop fresh fruits, jams, cans, jellies, beverages, natural spices, food additives and other products. It is an important economic tree species integrating greening, ornamental and food consumption, and has broad development prospects.

2 Propagation techniques of phenanthrene avocado

The reproduction mode of Philippine avocado is divided into sexual reproduction and asexual reproduction, sexual reproduction is seed reproduction, asexual reproduction is divided into tissue culture, cutting propagation, striping propagation, grafting propagation and so on.

2. 1 the cost of seed propagation is low, the reproduction coefficient is large, the method is simple and easy, and the obtained seedlings are robust, developed root system and strong resistance. It was found that storage time, soaking time, type and concentration of hormones had certain effects on the germination rate of phenanthrene avocado seeds. The germination rate of seeds decreased significantly with the extension of storage time, and when the seeds were soaked for 36 hours, the germination rate was higher, up to 86%. 10 mg / LIAA solution and 150 mg / L GA3 could make the seeds germinate earlier, accelerate the germination rate and increase the germination rate to a certain extent. Zhang Meng and others also confirmed this point and found that the seeds were taken out immediately after the fruit was harvested and rinsed in clean water for 24 hours and 11 days. The seedling emergence rate was as high as 93%, and with the extension of storage time, the seedling emergence rate decreased, and the seed stored in 4 ℃ refrigerator was better than fruit storage. The author found that the seeds were taken out immediately after harvest, washed, soaked in distilled water for 18 ~ 24 hours, raised seedlings at room temperature for 20 ℃, could emerge in 10 days, reached the seedling peak in 20 days, and the seedling emergence rate could reach 95% in 30 days. There was no need for hormone treatment to promote germination. When raising seedlings, the seedling tray should be prepared and sprayed with 800x KMnO4 to disinfect it.

The seedling substrate was evenly mixed with sand, fine soil and peat soil at 1 ∶ 1 ∶ 1, sterilized at high temperature and high pressure, and the treated seeds were placed on the plate and watered thoroughly. The treated seeds were spread evenly on the surface of the substrate, sprayed with 1000 times carbendazim solution, and the seedlings emerged in a greenhouse without direct sunlight of 15 ~ 25 ℃ after film mulching. When the emergence rate reached 50%, the film was opened and transferred to scattered light, when the seedling height was 3 cm and 4 true leaves were grown. It can be moved to the point plate or net bag, and the point plate seedling or net bag seedling can be bred. In order to solve this problem, asexual propagation technology has become a research hotspot because of the great variation of Philippine avocado, and it is difficult to maintain the excellent characters of mother tree in seed propagation.

2. 2 the leaves, stem segments, stem tips, seeds, stamens, pistils and flowers of phenanthrene can be used as materials for tissue culture. The leaves and stems of phenanthrene fruit contain a lot of polyphenols, which are easy to brown, and there are many endophytes. Disinfection time of disinfectants such as ethanol, mercury and sodium hypochlorite is a little longer, which can easily lead to browning, shorter disinfection time and easy contamination of materials. This is a major technical difficulty in tissue rapid propagation. Zeng Yanling and others took 1 ~ 2 lateral buds under the top bud as materials, washed 30min with running water and washed with distilled water for 2 ~ 3 times, followed by ethanol and 0.1% mercury. The budding rate was 0, the pollution rate was 20% ~ 40%, the callus rate was 20% ~ 40%, and the browning rate was 20% ~ 80%. Using the stem segment with bud of sterile seedling cultivated by seed as material, the budding rate was 100%, no pollution and no browning, and the optimal start-up medium was MS + 6-BA 0. 5 mg / L, the proliferation medium was MS + 6-BA 0. 2 mg / L + IBA 0. 2 mg / L, and the rooting medium was 1 / 2MS + IBA 0. 5 mg / L. Deng Wentao [1] treated stem segments with buds with 0. 1% and 0. 2% mercury for 6, 9 and 12 min respectively, the contamination rate could be controlled as 6% ~ 22%, and the suitable medium combination was MS + 6-BA 2 mg / L + IBA 1. 5 mg / L + NAA 0. 2 mg / L. Using flower organs as explants to induce callus, the contamination rate, browning rate and callus induction rate were 0 ~ 6%, 0 ~ 9% and 40% ~ 100%, respectively. The best medium for petal callus induction was MS + 6-BA 0. 5 mg/L + KT 1. 0 mg/L + 2 line 4-D 1. 0 mg/L. The best medium for ovary callus induction was MS+ 6-BA 2.0 mg/L+ KT 0.5 mg/L+ 2 mg/L+ 4-D 1.0 mg/L;. The best medium for anther callus induction was MS+ 6-BA 2.0 mg/L+ KT 0.5 mg/L+ 2 line 4-D 1.0 mg/L. During somatic embryogenesis with phenanthrene avocado seeds, the best method of seed sterilization is 1. 0%NaClO soaking for 12 hours. Jiang Jianping et al. [21] first disinfect 1min with 75% ethanol, wash once with sterile water, then disinfect 15 min with 2% geramine, wash once with sterile water, and finally disinfect 13 min with 5% NaClO plus several drops of Tween 80 and wash with sterile water for 4 times. this method is used for seed disinfection, the contamination rate is 0, while for stem segment disinfection, the contamination rate is as high as 95% ~ 100%, and the multiplication medium is MS + 6-BA1. 0 mg / L + IBA 0. 1 mg / L. The multiplication coefficient was 2.15 ~ 3.50, and the rooting medium was 1 / 2 MS + IBA 0.5 mg / L. Liu Hongzhang and others screened out that the best disinfection method of phenanthrene avocado explants was 70% ethanol, and the shoots and stems were disinfected with 0.1% mercury for 4 and 6 min respectively, and then inoculated to 1 / 2 MS + DTT 100mg / L + VC 100mg / L + streptomycin sulfate 100mg / L + carbenicillin 250 mg / L, the number of normal growing explants was as high as 95%. Wang Dan et al found that the optimal medium for callus induction from ovary, petal, calyx and stamen of Philippine avocado was MS+ 2 4-D 1.0 mg / L + KT 0.5 mg / L, MS+ 2 4-D 1.0 mg / L + NAA 0.1 mg + KT 1.0 mg / L, MS+ 2 4-D 1.0 mg / L + KT 1.0 mg / L, MS+ 2 4-D 2.0 mg / L + NAA 0.1 mg / L. Through the comparative experiment, it was found that the disinfection methods of the above stem segments and stem tips were not ideal, the terminal buds browned more easily than the stem segments, and the disinfection rate of semi-lignified branches was higher than that of full-lignified branches, but it was very easy to brown, so it was difficult to obtain materials without browning pollution and sprouting. Generally speaking, it is easy to obtain sterile seedlings from seeds as explants. The seeds were soaked in distilled water for 18 h, then disinfected with 75% ethanol for 30 s, washed with sterile water for 5 times, then treated with 0. 1% mercury for 7 min, rinsed with sterile water for 5 times, inoculated to MS medium, and germinated one after another on the 12th day. The techniques of disinfection and anti-browning of other explants need to be further studied, and the proliferation coefficient of sterile seedlings needs to be further improved.

2. 3 cutting propagation of phenanthrene avocado is a kind of tree species which is very difficult to root. In the process of cutting propagation, a certain concentration of rooting agent is often used to promote rooting. It was reported that the propagation mode of mother plant, the maturity of cuttings, the kinds of rooting agents, the concentration of rooting agents, the treatment time and the cutting medium all had certain effects on the rooting rate of cuttings. Deng Wentao et al used vermiculite as substrate, semi-lignified shoots of phenanthrene fruit as cuttings, soaked in IBA 200mg / L for 2 h, the average rooting rate was 88. 6%. 60%, the average root number is 7. 5%. 30, and the average root length is 17. 40 cm. Zhang Meng and other studies found that the rooting character of semi-lignified cuttings of 2-year-old seedlings was significantly better than that of other treatments, the rooting rate was 78. 5%. 95%, the average root number of cuttings was 6. 6%. The average root length is 15. 80 cm. Using perlite + rotten leaf soil as substrate, using Philippine oil fruit twig cuttings and soaking in IBA 1000 mg / L for 10 min, the rooting effect was the best, the rooting rate was 95. 20%, the average root number of cuttings was 4. 40, and the average root length was 14. 30 cm. Wang Chun et al used vermiculite + Reed + perlite as substrate and softwood cuttings were dipped in NAA 8 + ABT6 1500 mg / L for 2 s. Through the comparative experiment, it was found that the 2-year-old semi-lignified branches were taken from the cuttings of Philippine avocado, the cutting length was 5 ~ 10 cm, at least one bud was left, the upper part of the cuttings was trimmed into a flat mouth, and the lower part was trimmed into a 45 °oblique mouth, and the cuttings were quickly dipped in 1000 mg / L IBA or ABT solution for 10 s. The cuttings container was usually a hole plate or net bag. Before cutting, the hole tray, net bag and seedling bed were sterilized with 800x KMnO4, and the substrate could be sterilized under high temperature and high pressure if conditions were available. If the condition is limited, use KMnO4 to disinfect, plate and bag the substrate, water thoroughly, insert the hole on the substrate first, then insert the treated cuttings into the hole, and gently compact the substrate to make the lower part of the cuttings closely fit with the substrate, then spray an appropriate amount of 1000 times carbendazim solution, covered with plastic film, watering once every 10 days, combined with disease prevention spraying carbendazim, mancozeb, etc., can also spray appropriate amount of foliar fertilizer The cuttings with good root system were obtained after 60 days, which were planted 1 year later and fruited for 2 years.

2. 4 the asexual reproduction of Philippine oil fruit also includes grafting propagation, striping propagation and so on. There is very little research on this aspect in China, only Deng Wentao uses cutting grafting and skin tearing grafting, this method is suitable for the introduction and propagation of new varieties, and it is found that in the middle of May, sturdy disease-free and pest-free semi-lignified branches with 4 ~ 6 buds were selected as scions, and the survival rate was as high as 34%. Striping propagation can be divided into low striping and air crimping, the Lignification degree of phenanthrene oil fruit more than 2 years old is high, the branches are hard, and the branches are easy to be broken, so air striping can be selected, but there are few reports in this field at home and abroad. The seedlings introduced by Edouard Andre, a famous French botanist and horticulturist, from Brazil in 1890 are aerial striped seedlings. Through the striping experiment for nearly one year, Fachinello et al found that the branches were cut 10 cm from the ground and covered with soil 2 months later, and the plants with developed root system and good new shoot growth could be obtained after cultivation. Mielke et al confirmed the feasibility of striping propagation by studying the changes of many physiological indexes of striping. Striping propagation can be carried out all year round, usually in May. The branches with strong growth and free of diseases and insect pests are selected and gently engraved at 15 cm from the top of the branches. In order to avoid phloem healing, 3 mm can be ring engraved, hormone can be applied on the wound to promote wound healing and rooting, and then a plastic film with 15 cm in length and 10 cm in width is prepared, wound around the ring, fastened to the bottom, and the substrate is filled into the plastic film. And make the ring engraving place in the middle of the plastic film, after pouring enough water, tie up the upper end and arrange it into a funnel-shaped, so that it can be watered in the later stage, and the striping treatment can also be carried out after the ring engraving is healed. Although the air striping process is tedious and the breeding cycle is generally as long as 5 ~ 6 months, the survival probability is higher than that of cutting and grafting. If the breeding can be expanded, it can also alleviate the current situation that the supply of phenanthrene avocado seedlings falls short of demand to a certain extent, so it is a feasible method.