Abstract
Seeds of Xanthoceras sorbifolia Bunge were collected from two plantations and two superior trees in Inner Mongolia: and one plantation and one superior tree in Liaoning, China in late August, 2011. Yellowhorn or goldenhorn is an important tree species, from the aspects of source of edible oil and biodiesel and pioneering capacity of degraded and desert land. Characteristics investigated were seed length, width, and weight: weight and volume of 1,000 seeds: and weight and volume of one-liter seeds. The seeds of Qingsonglingxiang No. 1, growing alone in an open space, showed the highest values in seed length (16.08 mm), width (14.48 mm) and weight (1.40 g), while those of Tree No. 160 in Ar Khorqin Banner were the lowest ones: that is, 11.48mm for length, 11.81 mm for width, and 0.73 g for weight, respectively. Traits of seeds varied quite much between trees and among areas; for example, Tree No. 38 and No. 160 produced quite different seeds in several traits, although they are adjacent to each other in the same farm. Weight of 1,000 seeds varied from 718.0 g to 1,010.1 g and volume from 0.76 L to 1.52 L. Weight of one-liter seeds were 522.3 g to 688.2 g, while the number of seeds were 603 to 935. Seeds which were soaked in the water at $4^{\circ}C$ for 2 days showed the highest germination rate (89%) in a 30-day test, which was about 10% to 40% higher than those of non-treatment and dipping treatment at $36^{\circ}C$ followed by keeping under room temperature for 2 days. 81% of seeds in the wet sand at room temperature germinated, while 23% of seeds deprived of seed coat germinated. It is necessary to understand seed traits to select superior clones or provenances for the increased, unfluctuating production of seed.
