Lacebark pine （Pinus bungeana）, an evergreen conifer species native to China, is noted for its graceful profile. It has a height up to 30 m. Bark on young trees smooth, dull grey, scaling off in small patches like a...Lacebark pine （Pinus bungeana）, an evergreen conifer species native to China, is noted for its graceful profile. It has a height up to 30 m. Bark on young trees smooth, dull grey, scaling off in small patches like a plane tree, changing to chalky-white on old trunks, by which the species can be recognized from a long distance.展开更多
This experiment was conducted to evaluate the effect of seed priming on the germination and physiology of Pinus bungeana seeds. Seeds were treated by hydropriming with distilled water, halopriming with potassium nitra...This experiment was conducted to evaluate the effect of seed priming on the germination and physiology of Pinus bungeana seeds. Seeds were treated by hydropriming with distilled water, halopriming with potassium nitrate （KNO3） at -0.3, -0.6, -1.2 MPa respectively （untreated dry seeds were taken as control）. Properties of seed germination and physiology were determined and the effect of hydro- and halopriming on germination and physiology ofP. bungeana seeds were investigated. The results showed that, compared with control, each priming treatment had increased the germination percentage （GP） and germination index （GI）, shortened the mean germination time （MGT） and the time required for 50% of the seeds to germinate （Gs0）. Primed P. bungeana seeds significantly decreased the relative conductivity and the amount of malondialdehyde （MDA）. Of all the treatments applied to seeds of P. bungeana, halopriming at -0.3 MPa KNO3 produced the highest GP （65.0%） and the shortest MGT （l 8.8 d） and Gs0 （18.2 d）.展开更多
Pinus bungeana is a three-needle pine with typical fragmented distribution in central and northwestern China. Its natural resources are gradually decreasing and need to be conserved. For conserving genetic diversity o...Pinus bungeana is a three-needle pine with typical fragmented distribution in central and northwestern China. Its natural resources are gradually decreasing and need to be conserved. For conserving genetic diversity of P. bungeana, the authors sampled 10 natural populations in its distribution areas and conducted the analysis of isozymes. Thirty one loci with 53 alleles on the basis of 16 enzyme systems were assayed. The parameters of genetic diversity at species and population level are respectively as follows: As = 1.742, Ae[s] = 1.49, Ps = 54.8%, He[s] = 0.162, Ap = 1.39, Ae[p]= 1.30, Pp = 34.85, He[p] = 0.0986. In comparison with other pines, P. bungeana possesses a slightly low amount of genetic variation especially at the population level. By contrast, the level of population genetic differentiation (GST = 0.135) is higher compared to other pines. All ten populations are divided into three groups according to Nei抯 genetic identity (I). There is a slight relation (r = 0.31) between genetic distance and geographical distance. Some populations are obviously deviate from Hardy-Weinberg equilibrium but the total population is basically accordant with Hardy-Weinberg equilibrium. The correlation analysis between allele frequencies and ecological factors showed that the alleles at loci of Idh and Pgi-2 had gradient variation trends of their frequencies. The sample capturing curves?analysis indicated that the captured alleles increased when the number of sampled populations increased and 99% out of whole allele pool of ten populations would be captured when five populations were randomly selected. At last, the population genetic structure of P. bungeana and its conservation strategy were discussed.展开更多
文摘Lacebark pine （Pinus bungeana）, an evergreen conifer species native to China, is noted for its graceful profile. It has a height up to 30 m. Bark on young trees smooth, dull grey, scaling off in small patches like a plane tree, changing to chalky-white on old trunks, by which the species can be recognized from a long distance.
基金supported by the National Advantage Innovation Platform Project of China(No.0001108004)
文摘This experiment was conducted to evaluate the effect of seed priming on the germination and physiology of Pinus bungeana seeds. Seeds were treated by hydropriming with distilled water, halopriming with potassium nitrate （KNO3） at -0.3, -0.6, -1.2 MPa respectively （untreated dry seeds were taken as control）. Properties of seed germination and physiology were determined and the effect of hydro- and halopriming on germination and physiology ofP. bungeana seeds were investigated. The results showed that, compared with control, each priming treatment had increased the germination percentage （GP） and germination index （GI）, shortened the mean germination time （MGT） and the time required for 50% of the seeds to germinate （Gs0）. Primed P. bungeana seeds significantly decreased the relative conductivity and the amount of malondialdehyde （MDA）. Of all the treatments applied to seeds of P. bungeana, halopriming at -0.3 MPa KNO3 produced the highest GP （65.0%） and the shortest MGT （l 8.8 d） and Gs0 （18.2 d）.
基金the "Tenth Five-year Plan" National Key Project in Science and Technology (Grant No.2001-13)
文摘Pinus bungeana is a three-needle pine with typical fragmented distribution in central and northwestern China. Its natural resources are gradually decreasing and need to be conserved. For conserving genetic diversity of P. bungeana, the authors sampled 10 natural populations in its distribution areas and conducted the analysis of isozymes. Thirty one loci with 53 alleles on the basis of 16 enzyme systems were assayed. The parameters of genetic diversity at species and population level are respectively as follows: As = 1.742, Ae[s] = 1.49, Ps = 54.8%, He[s] = 0.162, Ap = 1.39, Ae[p]= 1.30, Pp = 34.85, He[p] = 0.0986. In comparison with other pines, P. bungeana possesses a slightly low amount of genetic variation especially at the population level. By contrast, the level of population genetic differentiation (GST = 0.135) is higher compared to other pines. All ten populations are divided into three groups according to Nei抯 genetic identity (I). There is a slight relation (r = 0.31) between genetic distance and geographical distance. Some populations are obviously deviate from Hardy-Weinberg equilibrium but the total population is basically accordant with Hardy-Weinberg equilibrium. The correlation analysis between allele frequencies and ecological factors showed that the alleles at loci of Idh and Pgi-2 had gradient variation trends of their frequencies. The sample capturing curves?analysis indicated that the captured alleles increased when the number of sampled populations increased and 99% out of whole allele pool of ten populations would be captured when five populations were randomly selected. At last, the population genetic structure of P. bungeana and its conservation strategy were discussed.
