Selection and breeding of a new high quality watermelon variety Guiling for dual planting in greenhouse facility and open field cultivation

【Objective】The purpose of the study was to select and breed new high-quality watermelon variety for dual planting in greenhouse facility and open field cultivation，to enrich the types of high-quality watermelon varieties of Guangxi，and to provide variety and technical support for the sustainable development of watermelon industry in Guangxi.【Method】In the autumn of 2013，a new combination of hybrid progeny G13-1×XFLL-11 was selected using G13-1 as the female parent and XFLL-11 as the male parent，and named Guiling watermelon in 2015. In 2016-2019，multipoint and multi-crop greenhouse facility cultivation and open field cultivation were synchronized for variety comparison test，regional test and production demonstration test.【Result】Guiling watermelon was a new variety of early-maturing medium-fruiting seeded watermelon，with a fruit development period of 27-30 d，a growth duration of 80-95 d for spring crops， and 60-80 d for summer and autumn crops. It had strong growth potential， strong resistance to disease and adversity， and was not prone to premature aging. The fruit was oval，the skin color was green covered with dark green stripes，the skin was smooth，the skin thickness was 0.7-1.0 cm，the texture of skin was hard and not easy to crack. The fruit flesh was big red and consistent，the flesh was fine and crispy，the center soluble solids content was 11.0%-12.0%，and it was sweet and refreshing，with excellent quality. The results of variety comparison test showed that the average weight of single melon in greenhouse facility cultivation was 2.2 kg，and the average yield was 49299.0 kg/ha，with an extremely significant yield increase of 14.7%（P＜0.01，the same below）over Xinggui No.3（control，the same below）；the average weight of single melon in open field cultivation was 3.6 kg，and the average yield was 30265.5 kg/ha，with an extremely significant yield increase of 21.4% over the control. The results of the regional test showed that the average weight of single melon in greenhouse facility cultivation was 2.1 kg，and the average yield was 46147.5 kg/ha，with an extremely significant yield increase of 13.9% over the control；the average weight of single melon in open field cultivation was 3.9 kg，and the average yield was 32100.0 kg/ha，with an extremely significant yield increase of 16.7% over the control. The results of the production demonstration test showed that the average yield of greenhouse facility cultivation was 39105.0- 50173.5 kg/ha，with an extremely significant yield increase of 11.2%-17.9% over the control；and the average yield of open field cultivation was 30415.5-37351.5 kg/ha，with an extremely significant yield increase of 13.6%-24.1% over the control. Guiling passed the national non-major crop variety registration in September 2019，with the registration number of GPD Watermelon（2019）No. 450376.【Conclusion】The new seeded watermelon variety Guiling is a good variety for dual planting in open field and facility cultivation，and can be used as fine watermelon production，which has high planting efficiency and can be popularized in areas suitable for watermelon cultivation.