It was first discovered in 1967 by Xu Liyuan of Shihezi 14 1 regiment of Xinjiang Production Corps in the No.2 watermelon production area of the Soviet Union. Originally named Ann Wu Yu, it has green and white skin, wide dark green stripes and pink flesh. During the period of 1984, Lee Seung-Hyun, Institute of Agricultural Sciences, Sixth Agricultural Division of Xinjiang Production Corps, used it to cultivate an unbranched watermelon variety, which was approved and popularized. The fruit of this variety is round, the skin is light green and reticulate, and the flesh is pink. The plant has no branches in the middle and upper parts of the main vine except the branches in the five nodes at the base. Moreover, the main vine is short and curved, the leaves are hypertrophy, and the growing point of the stem tip will stop growing and self-cap at the later stage of growth. This variety is not only suitable for close planting, but also does not need pruning in the field, which is beneficial to the industrial large-scale cultivation of watermelon. 199 1 year Lin Depei and others' early genetic research on unbranched traits showed that unbranched traits were controlled by a pair of single genes, which were recessive to normal branching traits and could be utilized through cross transfer.
2. short vine watermelon
Watermelon with short vines can be planted closely, which has been introduced from abroad for a long time. There are mainly two kinds: one is called Japanese short vine, which belongs to small cell type (dw 1dw 1), controlled by a pair of recessive genes, with dark green leaves, tufted leaves, inconspicuous main vine and early maturity, and the fruit development period is only16d; ; The other is called American short vine, which belongs to the type with few cells (dw2dw2), controlled by a pair of recessive genes, with light green leaves and main vine. The genes of two short vines are not equal, and the hybrid offspring is long vine, but both of them are characterized by small fruit (1 ~ 2 kg) and difficult fruit setting, so pure short vine varieties are rarely used directly, and generally used as parents to cultivate early-maturing watermelon varieties with small fruit shape. For example, Duanyang 1, a very early-maturing watermelon variety bred by Zhengzhou Fruit Research Institute of China Academy of Agricultural Sciences, and Guan Bao, bred by Taiwan Province Province. In addition, Japanese dwarf vine (dw 1dw 1) can also be used as an early marker to identify hybrid purity because of its short hypocotyl and dark green leaves.
Recent research shows that there are some other types of short vine watermelons. Huang et al. (1995) hybridized with Japanese short vine (dw 1dw 1) and American short vine (dw2dw2) respectively. F 1 generation is all long vines, and F2 generation has short vines besides DW, which shows that short vines are short vines.
Guobin Ma et al. (2004) showed that a dwarf vine material (P 1) introduced from the United States was controlled by two pairs of recessive genes, and its genotype was expressed as DW1DW1DW2DW2; Mid-vine material (P2) is controlled by a pair of recessive genes, and the genotype is DW1DW1DW2DW2; The self-selected long vine material (P3) contains no short vine gene, and its genotype is Dw 1Dw 1Dw2Dw2. A new watermelon strain SS 17 was bred by crossing with high quality common long vine watermelon P3. This strain has the longest middle vine about 1m, round fruit, flower skin, single melon weighing about 2kg, red flesh, easy fruit setting, good early maturity and central sugar1~12 degrees.
3. Plant leaf watermelon
The plate leaves are whole leaves or melon leaves. Because watermelons are basically cracked leaves, the leaves are particularly precious. Wang Yunhe et al. (1977) first reported the breeding of Banye 2 (round fruit, green and white skin, pink flesh, medium-sized seeds with brown and gray pockmarked seeds) × Soviet 3. Later, the Fruit Research Institute of China Academy of Agricultural Sciences found leaf mutation in early-flowering watermelon varieties, and bred a new leaf watermelon variety Zhongyu No.3 (Dayehong) with good comprehensive properties.
Because of the marker function of leaf traits, the first 3 ~ 4 leaves are obviously different from ordinary split-leaf watermelon, which can be used for early identification of hybrid seed purity. Therefore, with the popularization and popularization of watermelon heterosis breeding, more and more attention has been paid to the breeding and utilization of plate-leaf strains. Huang Shijie et al. (1985) bred a new leaf type variety Chongkai 1 (round fruit, dark green skin and big red meat) with Mibao× Zhongyu No.3, and bred a new watermelon hybrid variety Zhouyou No.8; Cui Dexiang et al. (1996) bred a new strain, Xinkai (round fruit, green skin, reticulation and big red meat), with the self-selected line X-4× Chongkai 1. Genetic research shows that the inheritance of leaf traits is controlled by a pair of genes, and the split leaf traits are recessive inheritance. Tianjin Seed Company bred a new watermelon variety Jinfeng 1 by crossing with the line with leaf traits as the female parent. F35, a new watermelon variety, was bred by crossing a leaf-bearing strain with its female parent in Kaifeng Vegetable Research Institute, Henan Province.
4. Germplasm with green characteristics after leaves.
Ma et al. (1995) found plants with the characteristics of green leaves (dg) in the field, and obtained excellent green line 96B90 through multiple generations of self-crossing. Its plants show that the color of new tissues or organs changes from yellow to white and green, and gradually turns to normal green with aging. For example, the color of newly unearthed cotyledons changed from yellow to white and green, and gradually turned green with the gradual aging of cotyledons, reaching the inherent green of varieties. Later, new shoots, young leaves and young stems were all like this. This trait is obviously different from normal green plants, and it can be shown as early as cotyledon stage (7 ~ 10d after sowing). It is an ideal marker for early identification of hybrid purity and has great research and utilization value (Figure 22- 12). Further research shows that the inheritance of post-green traits is controlled by a pair of recessive genes. The 96B90 strain itself has round fruit shape, dark green skin, red flesh and good quality, which can be directly used for cross breeding and cross transfer, and can be used to select new watermelon varieties with early identification of cross purity. A new watermelon variety Zhengguo 5506 was bred with 96B90 as the female parent in recent years. In June 2002, this technology won the national patent for technological invention.
Fig. 22- 12 Green watermelon vines behind leaves