Objective The experiment aims at estimating the seed germination characteristics and the response to drought stress of Pinus densiflora, Pinus sylvestris var. mongolica and Picea crassifolia which were widely used in arid area afforestation in north China. Pinus densiflora is a new species screened and verified in 2014 by the Liaoning Sand-Fixation Afforestation Research Institute. It grows well in Liaoning Province, and there is not any studies on its drought tolerance during seed germination. Gonghe County in Qinghai Province is a alpine sandy area. In order to provide reference for introducing Pinus densiflora in Qinghai sandy land, the tolerance of Pinus sylvestris var. mongolica and Picea crassifolia, two common sandy Pinaceae plants in Qinghai province, to drought stress were compared with Pinus densiflora.

Method Seed germination experiments were conducted using different concentrations of PEG-6000 solution to simulate the drought stress. The relative germination rate, relative root length, radicle length, vigor indexes, germination stress index and germination drought tolerance index of the three species were comprehensively evaluated by fuzzy membership function method.

Result Low concentrations of PEG-6000 improved seed germination and the radicle length of the three species. The seed germination, radicle length, seed flesh weights, vigor indexes, germination stress index and germination drought tolerance index of the three species showed a trend of increase in initial and then decrease with increasing PEG-6000 concentration. The tolerance to water stress was Pinus densiflora > Pinus sylvestris var. mongolica > Picea crassifolia.

Conclusion The drought tolerance of Pinus densiflora seed is superior to that of Pinus sylvestris var. mongolica and Picea crassifolia, which indicates that Pinus densiflora is suitable to be planted in Qinghai province.