How to allocate apple germplasm resources?

The general name of plants with certain genetic material and useful value in apple production and breeding. Including species, varieties and types of Malus, and related plants. Apple germplasm resources are the genetic material basis for cultivating new varieties or types of apples, and can also provide rootstocks for production, which is of great significance to the development of apple production.

Origin and distribution

There is no conclusive evidence of the exact origin of Malus. According to modern palynology, angiosperms originated in Cretaceous. Malus is a plant that has developed to an advanced stage in angiosperms, so its origin period should be some time after Cretaceous.

There have been different views on the origin center of Malus. In the Origin of Cultivated Plants (1882), A.De Candolle of Switzerland thinks that apples originated in southeastern Europe, western Asia and even Iran. Vavilov of the Soviet Union believed that apples originated in Central Asia, Asia Minor, the Near East and China. 1975 Soviet agricultural biologist zhukov (пмуковский) and Dutch A.G.Zeven wrote in the Dictionary of Cultivated Plants and Their Differentiation Centers. Central Asian origin center; Former Asian origin center; Euro-Siberian origin center; North American origin center (see the origin of cultivated fruit trees).

Classification and related plants

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Mareuse Mill. Botanically, it belongs to Rosaceae (Malinae). Malus is widely distributed in Asia, Europe and North America in the north temperate zone. There are about 35 species of this genus, among which Malus is the most. After long-term improvement, it has become an important cultivated fruit tree all over the world, and the rest are mostly important rootstocks or ornamental trees. 23 species of Malus have been found in China, which are widely distributed, but most of them are in Sichuan, Shaanxi, Gansu, Yunnan and other provinces. Most species of Malus can cross. The chromosome base of cultivated varieties is 17, and most varieties are diploid, that is, 2n = (4× 4)+(3× 6) = 34. However, regardless of species or varieties, the number of chromosomes changes, so there are two types of triploid and tetraploid.

Historically, there are classification methods of Malus, such as E.Koeh-ne according to whether sepals remain or not, and H.Zabel according to whether adult trees have cracked leaves or not. In 1920, A.Rehd-er divided Malus into five regions according to the state of young leaves at bud stage and whether mature leaves were split or not, among which Eumalus Zabel, Sorbo-malus Zabel and Chloromeles Rehd were closely related to fruit tree cultivation. Yu Dejun and others improved Leiter's classification method, and published the classification method of Malus in China in 1956. According to whether the leaves are divided, the state of young leaves rolling in the bud, the existence of stone cells and the persistence of fruit sepals, the Malus plants native to China are divided into 3 groups and 5 rows.

Fig. 1 The leaves of Eumalus Zabel don't split, but sweep in the bud; The fruit has no stone cells, and the sepals fall off or remain. Divided into the following 2 series.

Bakata Reid. Sepals falling off; Styles 3 ~ 5: The fruit is small, with a diameter of only 65438±0.5cm. There are the following six species in China: ① Vitex negundo (M.baccata(L.)Borkh. ) (figure 1). ② northeast Fraxinus mandshurica. ③ Macrobrachium rosenbergii. ④ Sikkim magnolia. ⑤ Begonia hupehensis. ⑥ Senecio hainanensis.

Apple (Pumila Rehd. ). Sepals persist; Style 5; The fruit shape is large, and the diameter is often more than 2 cm. There are six kinds of China: ⑦ apples (apples. ). 8 Shaguo. ⑨。 ). Attending begonia flower. ).？ Malus microphylla ? Xinjiang wild apple. ) Roma. ) Roma. ) (figure 2).

Fig. 2 The leaves of Za-bel of Sorbus often split and fold in bud: there are no stone cells or a few stone cells in the fruit; sepals fall off and sometimes persist. Divided into the following three lines: Sieboldia-nae Rehd. Sepals fall off, leaving a large depression: styles 3 ~ 5, hairy at the base; Leaves do not crack on fruiting branches, sometimes 3-5 cracks on growing branches, and sometimes do not crack; The fruit is small, round and seedless. There are 1 species: (13) wild silkworm in China.

Kansuenis Rehd。 In Longdong. Sepals fall off very late, leaving a small depression on the fruit after falling off, sometimes only partially falling off, or persistent: styles 3 ~ 5, smooth and hairless; Leaves split, different shades; The fruit is oval with a few stone cells or no stone cells. There are the following four species in China: [13] Schistosoma gansu. ⒂ Hawthorn. ). [14] Begonia variabilis. ). ⒄ Haitang. ).

Haitang in Dianchi Lake. ). Sepals persist; Style 5, glabrous or hairy; Leaf blade lobed or indehiscent: fruit subglobose with stone cells. There are four species in China: ⒅ prairie vole. Pet-name ruby begonia in Henan. ) ⒇ Begonia in Dianchi Lake. ) .310266 begonia cangjiang (m.ombro philahand.et mazz ).

3 10266 leaves of begonia. ) are shallow or undivided and folded in half in the bud; Styles 4-5, hairy at base; The atria extend to the base of the style, and the core is elongated into a spire; The fruit is 2 ~ 4 cm in diameter, and there are stone cells in the pulp. There are two species in China: 3 10266 Taiwan Province province (Taiwan Province cotton. ).3 10266 M.melliana Rehd。

Variety classification

As an important cultivated fruit tree, most varieties of apple originated from the cross between apple and other species. There are no exact statistics on cultivated varieties that have appeared in history, and it is generally believed that there are about 8000 species. For the classification of cultivated varieties, China used to classify them according to color, flavor and maturity in ancient times. /kloc-After the 6th century, European fruit scientists had many opinions on the classification of apple varieties, but no consensus was reached. /kloc-After the 9th century, apple varieties tend to be divided into 3 groups, 9 families and 27 groups according to maturity, fruit shape and color. However, due to the variety of apples, it is difficult to correctly classify the intermediate types by this method, and it is still difficult in practical application. After the 20th century, the classification of apple varieties was based on not only morphological characteristics, but also the genetic relationship among varieties, most of which were represented by one variety and divided into several varieties. In this way, American S.A.Beach divided nearly 700 apple varieties in new york into 10 variety groups. In the Journal of Apples in Hebei Province 1986 published by China, a variety classification method based on morphological and biological characteristics is proposed, and the classification level is: system-group-variety group-variety subgroup-variety-strain. Specifically, cultivated varieties are divided into begonia system (including begonia species group; Begonia variety group), sand fruit line (including red sand fruit population; White sand fruit population; Penang variety group), apple system (including China apple group, Xiamian apple variety group and Xiangguo population; Eurasian apple group, divided into 14 varieties). The classification of apple varieties is still developing and improving. The method of judging the genetic relationship among varieties and classifying them through isozyme zymogram analysis, pollen morphology observation and chromosome identification is still in the exploratory stage.

Related plants

There are 20 genera of related plants of Malus, all of which belong to Malus subfamily. They are native to China and belong to 16 genus. Some related plants as apple rootstocks can survive by grafting and play a role in dwarfing. For example, C.multiflorus Bge. ), Kaoko (C.submultiflorus Popov), Kaoko (C.acutifolia Turcz). ), etc. After grafting apple, the plant appears semi-dwarfed or dwarfed. Tristan Kappa Courths. Lysimachia christinae in Courths. The grafted apple has the effect of dwarfing and early fruiting. In addition, D. indi-cadone. Of the genus Docenia 3 1 1267; And some grafted apples. And a corpsman. It can also heal itself and has different degrees of dwarfing effect. However, after apple is grafted with exotic plants, there will often be different degrees of incompatibility, which will affect the plant life.

Development of Cultivated Varieties in China

In the history of China, the main apple trees were Lin Ling and Yan. At the latest in the 2nd century BC, there have been written records about the cultivation of forest age and Nai. Lin Shuo was originally produced in China, that is, sand fruit and bonus. The fruit can be eaten raw or processed. Mainly distributed in northwest and north China. Nai or cotton apple was introduced to Chinese mainland in the Western Han Dynasty. The origin remains to be verified, but it has been cultivated in China for about 2000 years, mainly distributed in Shaanxi, Gansu, Qinghai, Xinjiang and other provinces (autonomous regions).

Apple varieties cultivated in China were introduced from abroad in the late19th century, also known as western apples, to distinguish them from cotton apples. 187 1 introduced many varieties 10 from the United States, such as Yellow Newton Pippin, Red June, grevin Stein, Roxbury reddish brown, Autumn Pippin and Yellow Bellflower. From the early 20th century to 1930s, more and more varieties were introduced from the United States, Japan and other countries, including Ralls, Jonathan, Delicious, Golden Deli-cious, Ben Davis, McIntosh and White Pearmain. In addition to Shandong, Liaoning, Hebei and other coastal provinces, it has also been introduced to Shaanxi, Sichuan and other mainland provinces. Some of these varieties still play an important role in apple production in China. In 1950s and 1960s, more than 200 varieties were introduced from the Soviet Union and Eastern European countries, such as Ideality (мечта) and 600g Antonov Card (антоновк). Since 1950, fruit tree research and teaching units have carried out the breeding of new apple varieties (see apple breeding. Up to 1988, there are about 60 new varieties with good performance. After 1970, many new varieties were introduced from the United States, Japan and European countries, such as Red Star, Fuji (ふじ) and Jonakin. Some of them have been popularized.

Germplasm resources research

Collection and preservation

There are no more than 3,000 apple varieties or types that can be collected and properly preserved in the world. From the late 1970s to the early 1980s, all-Soviet Crop Cultivation Research Institute (всесо11023 ныйнаучр) The New York Agricultural Experimental Station has 1300 apple varieties and strains. In Asia, Japan has preserved more than 950 apple cultivars and wild and semi-wild varieties (1984). 1950, China began to organize a nationwide resource survey, which was later supplemented. Some new germplasm resources of Malus, such as Sikkim apple and Hubei apple, were found, which had apomixis characteristics. According to 1979- 1985 National Fruit Tree Science and Technology Development Plan, Fruit Tree Research Institute of China Academy of Agricultural Sciences (Xingcheng City, Liaoning Province) is responsible for establishing the National Apple Germplasm Resource Garden; Jilin Fruit Research Institute (Gongzhuling City, Jilin Province) is responsible for preserving the germplasm resources of cold-resistant small apples. 1988 National Apple Germplasm Resources Garden was built and passed the national acceptance, and about 700 apple varieties, cultivated varieties and types were preserved (1989).

Evaluation and utilization

It needs to be carried out on the basis of routine observation and character recognition. The routine observation of apple germplasm resources includes the observation and record of botanical characters, biological characters, adaptability, stress resistance and fruit economic characters. As the original material of apple breeding, many varieties have been observed and recorded in many countries for a long time. Through observation, the performance of some varieties was clarified, and some excellent varieties were screened out. Collect data and prepare various documents. 1905, the United States published Apples in new york, which recorded 673 varieties and some small apples in detail. 1982 The Soviet Union published "Apple Varieties Cultivated in the Soviet Union" (сортаяблоникулт). China was in There are 607 apple varieties recorded in "Apple Records of Hebei Province" published by 1986.

The efficiency of breeding work depends on mastering the quantity of germplasm resources and understanding the characteristics of resources. The purpose of trait identification is to have a deeper understanding of germplasm resources from the perspectives of physiology, genetics and cytology, especially for traits such as disease resistance, dwarfism and cold tolerance.

Germplasm resources of disease resistance and insect resistance

Diseases and insect pests seriously threaten apple production, and it is a common goal at home and abroad to cultivate disease-resistant varieties. In the United States, M.floribunda(Zuccagni)Schneid. With scab-resistant resources as parents, through several generations of hybridization, a disease-resistant variety Freedom was bred. According to the research data at home and abroad, the tolerance of some species and cultivated varieties of Malus to pests and diseases is shown in table 1.

Table 1

Table 1 compressive strength

Many species native to China have strong resistance to the low temperature in winter. For example, Vitex negundo can withstand the low temperature of -40℃ and resist drought; Vitex negundo has strong cold resistance and resistance to apple rot. Begonia is cold-tolerant, drought-tolerant and salt-tolerant. As a rootstock, it is widely used in production and often used as the original material for cold-resistant breeding. Table 2 lists the stress resistance of some Malus plants. Amomum villosum, which originated in China, has strong cold resistance, drought resistance and salt tolerance, and can be used as rootstock. After 1950, China began to breed cold-resistant varieties, and successively bred cold-resistant varieties or excellent lines such as Jinhong, Jiuguang, Justin, Xinhua, Futian, Donghong, Qiu Shuang and Guang Bei. It can resist the low temperature of -30℃ in winter in the breeding ground. Cold-tolerant varieties introduced from abroad, such as American sour apples (M.adstringens), include Olga, Dolgo, Hopa, Hyslop, Soulard, etc. Siberian sour apples (M.robusta) in the Soviet Union include begonia (Фтаяранстка) and Huang Taiping (еура). The varieties with strong cold resistance include Phoenix Egg, Begonia Fruit, Jinqiu, Sweet Isei Baby, Jiang Jie No.4 and so on. There are Chiyang, Huang Kui, Mei Erba and Huajia.

Table 2 Dwarfs

Mi (short for meter)) Milla variety Para-Di Siaka Schneider. And Kentucky bluegrass. It is an important resource for dwarf rootstock breeding. They all have different degrees of dwarfism and many types. After collecting more than 70 types from Britain, France, Germany, Netherlands and other countries and classifying them, the M series rootstocks with different dwarfing effects were screened out, among which M9, M8, M20, M2 1 and M26 were dwarf and extremely dwarf. China native begonia, Shaguo, Longdong begonia, mosaic begonia, hawthorn, Dianchi begonia, Sikkim begonia, etc. Some varieties or types of them appear dwarfing in different degrees after grafting with apples. These dwarfing resources can be used as parents to cultivate dwarfing rootstocks or varieties. Among apple varieties, the short branch variety is a naturally occurring bud mutation with dwarfing characteristics. As parents, some varieties with short branch bud mutation have high short branch offspring rate. For example, in 1969, K.O.Lapins reported that Xu's short-branch bud McIntosh Wijicik crossed with Golden Crown, and the proportion of short-branch offspring reached 43.9%. It is considered that its compact character is controlled by a pair of dominant single genes, and another bud of Xu also has this characteristic. Other varieties that pass on dwarfing traits to their offspring are Melba, Green Banana, Alkman and so on. However, Redjade, Junxiu and Galliami are parents, and the probability of short-branched offspring is very low. Short branch bud mutation can also be used to cultivate dwarf varieties. In addition to the dwarfing types of Marshal line and Jinguan line, there are short-branched Fuji line (such as Changfu No.3), short-branched Xu (McIntosh short branch), short-branched Mor short branch, short-branched Australian green apple (Australian green apple short branch), Yanqing (green banana short branch bud mutation), new Marshal (Marshal short branch bud mutation), and Chinese rose bred by China. As parents, it is necessary to identify and study the transmission ability of these short-branch budding varieties (lines) to their offspring.

Early fruiting and high yield

The varieties bearing early fruits after grafting are Qinguan, Jiguan, Jinguan, Shengsheng, Jinhong, Tian, Zaojinguan, Liaofu, Pa Piloff Ka, Xu, Hongyu and Huajia. Qin Guan, Ji Guan, Jin Guan and Jin Aisheng not only bear fruit early, but also have high yield. The achievements are long overdue, including Junxiu, Chilong, Emerald, Fei Zhiyi, Qinglong, Daikin and so on. Marshal, Red Star, India and Guoguang, which were widely cultivated, began to bear fruit later.

parthenogenesis

Most species of apomixis in Apple are polyploid. Malus sikkimensis is triploid, belonging to Malus hupehensis and Malus keruiensis (M.coronaria(L.)Mill. ), needle apple (M.la-nceofolia), flat apple (M.platycarpa) and mutant apple (Malus variabilis) are triploid and tetraploid. Begonia placentae ) There are diploid, triploid and tetraploid types; There are diploid, triploid, tetraploid and pentaploid types of Malus trifoliata. The diploid types of Shajinhaitang and Malus trifoliata may be sexual.

Polyploid variety

Most apple varieties are diploid. It is reported that the frequency of triploid seedlings of diploid varieties is 0.3%. Triploid varieties have been paid attention to in cultivation and breeding practice because of their vigorous plant growth, large fruit, low fertility, high yield and strong stress resistance. The important triploid varieties are Jonah Gold, New Jonah Gold, Beidou, Lu Ao, Fuhuapii, Red Dragon, Great Coral, Red Coral, Spi Gold, New Golden Crown and so on.

There are few tetraploid varieties. There are many tetraploid buds in apple cultivars, but they are all different types of chimeras. Diploid varieties pollinate triploid varieties, and tetraploid seedlings can appear. The variety thus bred is Alfa 68 from Sweden, which shows that the tree is vigorous and the weight of a single fruit can reach 400 ~ 700g g.

Ornamental resources

Apple plant with ornamental flowers, fruits and leaves. Some varieties have bright colors or double petals. For example, begonia pendula is an ancient ornamental tree species in China. Red-fleshed apples are native to Xinjiang, China, and the red-leaf paradise introduced from the Soviet Union and the United States has the characteristics of tender buds and petals, which can be viewed. The fruit of Yinnv (ァルプス), a cultivated variety introduced from Japan, has both edible value and ornamental value. In addition, some small and colorful varieties can also be used for ornamental or potted plants.