天美55是以稳定自交系‘E-181为母本、纯化自交系‘E-158为父本选育而成的薄皮甜瓜杂交1代新品种。该品种春季大棚栽培果实发育期28 d左右，全生育期88 d左右。植株长势旺盛，综合抗性突出，孙蔓结果为主。果实筒形，单果质量650 g，果长18 cm，宽10 cm，果肉厚度3.0 cm。果皮白色，果肉白色，可溶性固形物含量（w，后同）15%，肉质酥脆，香味浓郁，口感好，667 m2产量3 500 kg以上，适合华北、西北等地区春季保护地和露地栽培。2018年通过中华人民共和国农业农村部品种登记。

关键词： 薄皮甜瓜; 新品种; ‘天美55; 杂交1代

Abstract： ‘Tianmei 55 is a new thin-skinned Melon Hybrid F1 generation， which was bred from stable inbred line ‘E-181 as female parent and pure inbred line ‘E-158 as male parent. The fruit development period is about 28 days and the whole growth period is about 88 days in spring greenhouse cultivation. The plants grow vigorously， the comprehensive resistance is prominent. It is a Samson variety. The fruit is cylindrical in shaped with white skin and white flesh， 650 g in weight， 18 cm in length， 10 cm in width and 3.0 cm in flesh thickness. The soluble solids content is 15%， the flesh is crisp with good flavor. The 667 m2 yield is more than 3 500 kg. It is suitable for spring conservation and open cultivation in North China， Northwest China and other areas.

Key words： Striffen muskmelon; New variety; ‘Tian Mei 55; F1 Hybrid

1 育种目标

甜瓜属葫芦科黄瓜属作物，甘甜可口，风味芳香，是餐后的高档果品，故多年稳居国际市场十大畅销果品之列。近年来，随着国内人们生活水平的迅速提高和甜瓜生产的发展，甜瓜既是馈赠亲友的高档礼品，又是大众喜食的水果之一。设施栽培是在现代科技与经济的基础上发展起来的高效优质作物栽培生产，是农业现代化发展的方向。自20世纪90年代末开始，以日光温室、塑料大棚等设施栽培方式的甜瓜生产迅速发展，在山东、河北等地形成了大规模的集中产区，创造了巨大的经济效益和社会效益，尤其是早春设施栽培薄皮甜瓜，经济效益十分显著[1-4]。河北省青县、乐亭，山东省青州、聊城等地已成为全国早春设施栽培薄皮甜瓜的主产区。‘银瓜是山东省的主栽薄皮甜瓜品种之一，植株生长势较强，早熟，肉质酥脆，可溶性固形物含量较低，不耐贮运。为满足日益变化的生产需求，针对‘银瓜早熟、口感好但可溶性固形物含量较低、不耐贮运的特点，天津科润蔬菜研究所将育种目标确定为：培育适合早春保护地及露地栽培、早熟、可溶性固形物含量（w，后同）15%、耐贮运、抗性强的杂交薄皮甜瓜新品种。

1 breeding objectives

Melon is a Cucumis crop of Cucurbitaceae. It is sweet and delicious with fragrant flavor. It is a high-grade fruit after dinner. Therefore, it has been ranked among the top ten best-selling fruits in the international market for many years. In recent years, with the rapid improvement of domestic people's living standards and the development of melon production, melon is not only a high-grade gift for relatives and friends, but also one of the fruits loved by the public. Protected cultivation is an efficient and high-quality crop cultivation and production developed on the basis of modern science and technology and economy. It is the direction of agricultural modernization. Since the late 1990s, melon production by means of facility cultivation such as solar greenhouse and plastic greenhouse has developed rapidly, forming a large-scale centralized production area in Shandong, Hebei and other places, creating huge economic and social benefits, especially the facility cultivation of thin skinned melon in early spring [1-4]. Qingxian and leting in Hebei Province, Qingzhou and Liaocheng in Shandong Province have become the main production areas of thin skinned melon in early spring‘ Silver melon is one of the main thin skinned melon varieties in Shandong Province. It has strong plant growth potential, early maturity, crisp meat, low soluble solid content and is not resistant to storage and transportation. In order to meet the changing production demand, in view of the characteristics of 'silver melon' which is early maturing, tastes good but has low soluble solid content and is not resistant to storage and transportation, Tianjin Kerun Vegetable Research Institute has determined the breeding goal as: to cultivate a new hybrid thin skinned melon variety suitable for early spring protected and open field cultivation, early maturing, soluble solid content (W, the same later) 15%, resistant to storage and transportation and strong resistance.

2 选育过程

2.1 亲本来源及特征特性

2.1.1 母本的选育及特性 母本‘E-181是2008年利用山东地区农家品种‘银瓜經6代选育的纯自交系，早熟，全生育期88 d，果实发育期28 d。果皮白色，果肉白色，中心可溶性固形物含量12%，单果质量700 g，果形指数2.37，棒形，具有早熟、肉质酥脆的特点。

2.1.2 父本的选育及特性 父本‘E-158是2008年利用日本品种与河南地方品种杂交后，经6代自交纯化后，选用2个优良株系混选后再自交纯化的稳定株系。植株长势较旺，以孙蔓结果为主，中熟，全生育期90 d，果实发育期约30 d，果实正梨形，果皮白色，成熟后有黄晕，单果质量500 g左右。果肉白色，中心可溶性固形物含量16.0%以上，肉质脆，抗性强。

2.2 选育经过

2011年春季用‘E-181作母本，用‘永甜‘白沙蜜‘E-158‘E-159‘E-161等9个白皮甜瓜品种作父本配制组合，秋季进行组合筛选试验，根据果实性状及田间表现综合筛选，‘E-181×E-158和‘E-181×E-1612个组合表现突出，初步入选。2012春季继续试种，‘E-181×E-158在产量、口感、抗病性表现优良，为中选组合。2012年秋季、2013年春季以‘青县羊角脆为对照进行品种比较试验，该品种产量、口感、抗性等性状均优于对照。2014—2015年进行多点区域试验，2016年进行生产试验，该品种表现突出，定名为‘天美55。2018年通过中华人民共和国农业农村部品种登记，品种登记号：GPD甜瓜（2018）120720。

3 试验结果

3.1 组合筛选试验

2012年用32个组合初选保留选配的9个杂交组合进行再一次组合筛选试验。以‘青县羊角脆为对照品种，‘E-181×E-158组合667 m2产量比对照增产20.3%，中心可溶性固形物含量比对照提高3.7%，且该组合抗性好于对照。

3.2 品种比较试验

2012年秋季、2013年春季连续2 a（年）在天津农业科学院武清创新基地三连栋塑料大棚内进行品种比较试验，小区面积5.4 m2，每小区种植16株，3次重復，田间随机区组排列，株行距40 cm×80 cm，以‘青县羊角脆为对照品种。2012年秋季7月20日播种，7月31日定植;2013年春季3月1日播种，3月30日定植，均采用穴盘育苗。2次品种比较试验表明（表1），‘天美55果实发育期平均为27 d，比对照少3 d;单瓜质量0.62 kg，平均小区产量为26.1 kg，较对照提高20.5%，增产效果明显;可溶性固形物含量15.5%，比对照高2.9个百分点。果皮白色，成熟后微有黄晕，果肉白色，筒形，果肉厚，种腔小，肉质脆，香味浓郁。

3.3 区域试验

2014—2015年春季在天津市宝坻区石辛庄、河北青县、山东莘县、青州等地冷棚中进行多点区域试验，每个区域设3次重复，以‘青县羊角脆为对照，试验结果（表2）显示，‘天美55在4个区域产量均高于对照，平均增产20.4%;平均单瓜质量0.62 kg，较对照高0.1 kg;果实发育期平均为27.6 d，比对照短2.4 d;可溶性固形物含量平均15.7%，比对照高3.0个百分点。

3.4 生产试验

2016年春季在河北青县、山东莘县、青州等地进行生产试验，以‘青县羊角脆为对照，小区面积32 m2，定植100株，不设重复。河北青县和山东青州为冷棚种植，山东莘县为暖棚种植，均为吊蔓栽培，单蔓整枝，定植密度为0.4 m×0.8 m。试验结果（表3）显示，‘天美55在3个种植点产量均高于对照，平均增产为21.6%;平均单瓜质量0.62 kg，较对照增加0.11 kg;果实发育期平均为28.0 d，比对照短3.6 d;可溶性固形物含量平均为15.4%，比对照高3.0个百分点。‘天美55在低温下坐果整齐，果形周正，筒形，田间表现综合抗性较对照强。

2 breeding process

2.1 parental sources and characteristics

2.1.1 breeding and characteristics of female parent 'e-181 is a pure inbred line selected through 6 generations by using the Agricultural Variety' YINGUA 'in Shandong in 2008. It is early maturing, with a total growth period of 88 days and a fruit development period of 28 days. The pericarp is white, the pulp is white, the content of soluble solids in the center is 12%, the single fruit mass is 700 g, the fruit shape index is 2.37, rod-shaped, with the characteristics of early maturity and crisp meat.

2.1.2 breeding and characteristics of male parent 'E-158' is a stable line that was hybridized with Japanese varieties and Henan local varieties in 2008, after 6 generations of self purification, selected two excellent lines, and then self purified. The plant grows vigorously, mainly sun man fruit, medium mature, the whole growth period is 90 days, the fruit development period is about 30 days, the fruit is pear shaped, the peel is white, there is yellow halo after maturity, and the single fruit weight is about 500 g. The pulp is white, the content of soluble solids in the center is more than 16.0%, the meat is crisp and has strong resistance.

2.2 breeding process

In the spring of 2011, 'e-181' was used as the female parent, and nine white skin melon varieties such as' Yongtian 'baishami' E-158 'e-159' e-161 'were used as the male parent. In the autumn, the combination screening test was carried out, and' e-181 'was comprehensively screened according to the fruit characters and field performance × E-158 and 'e-181 × E-1612 combinations showed outstanding performance and were preliminarily selected. Continue planting in spring 2012, 'e-181' × E-158 has excellent performance in yield, taste and disease resistance, so it is the selected combination. In the autumn of 2012 and spring of 2013, the variety comparison test was carried out with 'Qingxian Yangjiao crisp' as the control. The yield, taste, resistance and other characters of the variety were better than those of the control. The multi-point regional test was carried out from 2014 to 2015 and the production test was carried out in 2016. The variety has outstanding performance and is named 'Tianmei 55'. In 2018, it passed the variety registration of the Ministry of agriculture and rural areas of the people's Republic of China, variety registration No.: GPD melon (2018) 120720.

3 test results

3.1 combined screening test

In 2012, 32 combinations were selected and 9 hybrid combinations were retained for another combination screening test. 'Qingxian Yangjiao crisp' was used as the control variety, 'e-181' × The 667 M2 yield of E-158 combination was 20.3% higher than that of the control, and the content of central soluble solids was 3.7% higher than that of the control, and the resistance of the combination was better than that of the control.

3.2 variety comparison test

In the autumn of 2012 and the spring of 2013, the variety comparison test was conducted in the three multi span plastic greenhouse of Wuqing innovation base of Tianjin Academy of Agricultural Sciences for two consecutive years. The plot area was 5.4 m2, 16 plants were planted in each plot, repeated for three times, arranged in random groups in the field, and the row spacing of plants was 40 cm × 80 cm, with 'Qingxian Yangjiao crisp' as the control variety. In the autumn of 2012, it was sown on July 20 and planted on July 31; In the spring of 2013, it was sown on March 1 and planted on March 30. All seedlings were raised by hole tray. The results of two varieties comparison tests (Table 1) showed that the average fruit development period of 'Tianmei 55' was 27 days, which was 3 days less than that of the control; The weight of single melon was 0.62 kg, and the average plot yield was 26.1 kg, which was 20.5% higher than that of the control; The content of soluble solids was 15.5%, 2.9 percentage points higher than that of the control. The pericarp is white, slightly yellow halo after maturity, the pulp is white, cylindrical, the pulp is thick, the seed cavity is small, the meat is crisp and the flavor is rich.

3.3 area test

From the spring of 2014 to 2015, multi-point regional trials were conducted in Shixinzhuang, Baodi District, Tianjin, Qingxian County, Hebei, Xinxian County, Shandong and Qingzhou. Each region was set up for three repetitions. Taking "Qingxian Yangjiao crisp" as the control, the test results (Table 2) showed that the yield of "Tianmei 55" in the four regions was higher than that of the control, with an average increase of 20.4%; The average weight of single melon was 0.62 kg, which was 0.1 kg higher than that of the control; The average fruit development period was 27.6 days, 2.4 days shorter than the control; The average content of soluble solids was 15.7%, 3.0 percentage points higher than that of the control.

3.4 production test

In the spring of 2016, production experiments were carried out in Qingxian County, Hebei Province, Xinxian County, Shandong Province, Qingzhou and other places. Taking "Yangjiao crisp in Qingxian County" as the control, the community area was 32 m2, and 100 plants were planted without duplication. Qingxian County, Hebei Province and Qingzhou County, Shandong Province are planted in cold shed, and Xinxian County, Shandong Province is planted in warm shed. Both of them are cultivated by hanging vine, single vine pruning, and the planting density is 0.4 M × 0.8 m。 The test results (Table 3) show that the yield of Tianmei 55 at the three planting sites is higher than that of the control, with an average increase of 21.6%; The average weight of single melon was 0.62 kg, increased by 0.11 kg compared with the control; The average fruit development period was 28.0 days, which was 3.6 days shorter than the control; The average content of soluble solids was 15.4%, 3.0 percentage points higher than that of the control‘ Tianmei 55 has neat fruit setting under low temperature, round and cylindrical fruit shape, and the comprehensive resistance in the field is stronger than that in the control.

4 品种特征特性

早熟杂交1代薄皮甜瓜新品种。植株长势旺盛，田间表现综合抗性较好，以孙蔓结果为主。果实发育期27 d，果实筒形，单果质量650 g，果长18 cm，果宽10 cm，果肉厚度3.0 cm。果实筒形，果形指数1.8，果皮白色，果实成熟后有黄晕，果肉白色，可溶性固形物含量15%，肉质酥脆，香味浓郁，口感好。具有果形漂亮、早熟、高糖、品质佳、坐果整齐度好，抗性强等特点，667 m2产量3 500 kg以上（见封面、彩插4）。

5 栽培技术要点

‘天美55适宜于保护地和露地栽培。栽培要点如下：

（1）种子处理：种子采用温汤浸种。（2）施肥：667 m2施入充分腐熟的鸡粪2 000 kg（或土粪5 000 kg）+复合肥30 kg作基肥;667 m2再加施磷酸二胺30 kg、硫酸钾20 kg作为追肥。（3）定植密度：保护地单蔓整枝667 m2保苗2 000～2 300株;露地采用2～4蔓整枝667 m2栽1 200株。（4）植株调整：保护地吊蔓栽培时，主蔓4片真叶时摘心，可单蔓或双蔓整枝。单蔓整枝：主蔓摘心后选留1条长势健壮的侧蔓。以下的侧枝及时摘除，在所留侧枝5～9片叶发出的孙蔓上选留3～4瓜作为第1茬瓜，留瓜孙蔓留2片叶摘心。10～20片叶发出的侧枝要打掉，植株长势弱时，此处侧枝可保留2片叶摘心。第1茬瓜基本定个后，20～22片叶的孙蔓可再留瓜2～3个，顶部的侧枝打掉，但每株要保留2～3个生长点，维持植株长势，防止植株早衰。双蔓整枝：主蔓摘心后选留2条长势健壮一致的侧蔓。分别在2条蔓6～10节上发出的孙蔓各留2～3个瓜。注意2条蔓留瓜的节位和幼瓜的大小要一致，否则会导致大吃小现象。此后，根据植株长势可决定是否留二茬果。无论单蔓还是双蔓，每株要留3～4个长势一致，大小均匀的瓜才能保证产量。（5）水肥调控：果实乒乓球大时，及时浇膨果水和追肥，667 m2追肥20 kg硝酸钾或高钾水溶肥。（6）保证通风透光，降低湿度，预防病害的发生。（7）采收前7 d禁止浇水，避免果实糖度的降低;果实成熟时应及时采收，清晨采收果实品质最佳[5]。

4 variety characteristics

A new variety of early maturing hybrid 1 generation thin skinned melon. The plant grew vigorously and showed good comprehensive resistance in the field, mainly sun man fruit. The fruit development period is 27 days, the fruit is cylindrical, the single fruit weight is 650 g, the fruit length is 18 cm, the fruit width is 10 cm, and the pulp thickness is 3.0 cm. The fruit is cylindrical, the fruit shape index is 1.8, the peel is white, the fruit has yellow halo after ripening, the pulp is white, the content of soluble solids is 15%, the meat is crisp, the flavor is rich, and the taste is good. It has the characteristics of beautiful fruit shape, early maturity, high sugar, good quality, good fruit setting uniformity and strong resistance. The output of 667 M2 is more than 3500 kg (see cover and color insert 4).

5 key points of cultivation techniques

Tianmei 55 is suitable for cultivation in protected and open fields. The key points of cultivation are as follows:

(1) Seed treatment: seeds are soaked in warm soup. (2) Fertilization: 667 m2, 2000 kg of fully decomposed chicken manure (or 5000 kg of soil manure) + 30 kg of compound fertilizer as base fertilizer; 667 M2 plus 30 kg diamine phosphate and 20 kg potassium sulfate as topdressing. (3) Planting density: 667 m2 per vine in the protected area, 2000 ~ 2300 seedlings; In the open field, 2 ~ 4 vines are used to prune 667 m2 and 1200 plants are planted. (4) Plant adjustment: in the cultivation of hanging vine in the protected area, when the main vine has 4 real leaves, it can pick the heart, and it can be pruned by single vine or double vine. Single vine pruning: after the main vine picks the heart, select and leave a strong side vine. The following lateral branches shall be removed in time, and 3 ~ 4 melons shall be selected as the first crop of melon on the sun vine from 5 ~ 9 leaves of the left lateral branches, and 2 leaves shall be left for the sun vine to pick the heart. The lateral branches from 10 ~ 20 leaves shall be knocked off. When the plant growth is weak, 2 leaves can be retained here to pick the heart. After the first crop of melon is basically fixed, 2 ~ 3 melons can be left for the grandson vine with 20 ~ 22 leaves, and the side branches at the top shall be destroyed, but 2 ~ 3 growth points shall be reserved for each plant to maintain the plant growth and prevent premature aging of the plant. Double vine pruning: after the main vine picks the heart, select and leave 2 side vines with strong and consistent growth. Leave 2 ~ 3 melons for the sun vine on 6 ~ 10 nodes of 2 vines respectively. Note that the node position of the two vine melons should be consistent with the size of the young melons, otherwise it will lead to big eating and small eating. After that, whether to keep the second crop of fruit can be determined according to the plant growth. Whether single vine or double vine, each plant should leave 3 ~ 4 melons with consistent growth and uniform size to ensure yield. (5) Water and fertilizer regulation: when the fruit table tennis is large, it shall be watered with swelling fruit water and topdressing in time, 667 M2 topdressing, 20 kg potassium nitrate or high potassium water-soluble fertilizer. (6) Ensure ventilation and light transmission, reduce humidity and prevent diseases. (7) Watering is prohibited 7 days before harvest to avoid the reduction of fruit sugar content; The fruit should be harvested in time when it is ripe, and the fruit quality is the best when harvested in the morning [5].