Breeding report of a new seedling guava cultivar Suibai No. 1

Suibai No. 1 is a novel red- fleshed guava cultivar selected from local red- fleshed seedling populations in Guangzhou, distinguished by its comprehensive superior traits. It originated from an outstanding guava germplasm discovered in Zengcheng District, Guangzhou, in 2002, characterized by green peel, red flesh, tender texture, and a pronounced aroma. This germplasm was subsequently propagated by seed. In 2006, 150 seedlings were obtained, which were transplanted to the Jiufo Experimental Base of the Guangzhou Institute of Pomology in 2007. Phenological, morphological, and fruit quality traits were systematically evaluated, leading to the selection of six elite individuals (B series). The top three genotypes were propagated by cuttings in 2008. By 2010, a batch of rooted cuttings was established at the same base for further trait observation. In 2017, scions from the clonally propagated B4 line- identified as the most promising genotype- were grafted onto pearl guava rootstocks for variety comparison and regional trials in Guangzhou. This genotype was officially released as Suibai No. 1. The tree exhibits yellowish-brown and smooth bark, an upright growth habit, vigorous growth, and an open canopy. Mature trees reach a height of 2.15 m with a trunk circumference of 33.6 cm and a crown spread of 2.11 m×2.03 m. New shoots are green and quadrangular, becoming cylindrical after maturation. Leaves are light green when young, turning dark green at maturity; they are simple, opposite, and oblong-elliptic. Young branches are densely pubescent, becoming glabrous and dull grayish-brown with age. Flowers are solitary or in clusters of 2-3, with complete floral structure. The receptacle is yellowgreen, petals are imbricate and white, filaments are slender, and the calyx is green, campanulate or pyriform, and persistent. Fruits have an average weight of 225.0 g and an oval shape (fruit shape index 1.19). The peel is glossy yellow-white; the flesh is white, tender, and smooth. Seeds are few, irregularly shaped, moderately hard, and light yellow. The flavor is sweet and sour with a strong aroma. Fruit biochemical composition includes soluble solids content (11.0%), soluble sugar (7.7 g · 100 g- 1 ), titratable acidity (3.16 g·kg-1 ), and vitamin C (176.6 mg·100 g-1 ). The fruit development period varies seasonally: 70-90 days from flowering to maturity in summer, and 110-130 days in winter. The cultivar shows resistance to anthracnose and tolerance to high temperatures, but is not cold-hardy. Annual fertilization is recommended 5-6 times. Seedlings should receive readily available nitrogen, phosphorus, and potassium fertilizers, while mature trees should be fertilized according to tree size and fruit load. Flower and fruit thinning should be conducted in combination with production season management to improve fruit set. Bagging is recommended to protect against fruit flies, other pests, and birds. Suibai No. 1 displays stable varietal traits following vegetative propagation. It is characterized by high yield stability, excellent fruit quality, desirable texture, and strong aroma, making it a valuable cultivar worthy of widespread promotion and cultivation.