Fruits And Seeds Characteristics Of Pinus Tabulaeformis In Loess Plateau

Pinus tabulaeformis,with strong adaptability to resist the drought and barren,and to protect soil,water and ecological environment well,was the main afforestation species in the Loess Plateau.The geographical variations of the forest were universal because of the strong climate difference in the distribution area.Pinus tabulaeformis grew better with rich rainfall and better sites against worse forest in worse sites.In order to understand differences of phenotypic traits and natural regeneration regularity of Pinus tabulaeformis in the distribution of plantation area in the Loess Plateau area.10 Pinus tabulaeformis plantation area(Fuxian,Ganquan,Hequ,Huating,Huangling,Huanglong,Jixian,Jingyuan,Xifeng,Xunyi of Ningxia,Shaanxi,Gansu and Shanxi Province with plantation forest widely distributed)were chosen to collect the cones and then measured and analyzed the cones,seeds and seedlings.With the use of grading classification,principal component and cluster statistical analysis to evaluate cones and seeds,membership function model to evaluate the differences.The results showed that:(1)There were significant differences in cones,seeds and seedlings in each Pinus tabulaeformis area.Cones variation range were from 9.57% to 37.33%,while seeds characters with 9.57%~63.47%.Cone length,cone width,cone weight,wings length,seed length,seed width,aspect ratio,germination rate and life force were completely accord with normal distribution,while water content,maturity ratio,cones length-width ratio,seed thickness,thousand seeds weight,germination potential and seed vigor did not conform to the normal distribution.Cone length of Xifeng in Gansu(65.02 mm)and JingYuan in Ningxia(62.81 mm)area were larger obviously than others,while Fuxian(22.43 mm)was the least;seed length(8.04 mm)of Jingyuan was biggest,while Hequ owned least(6.80mm)seed length.Cone weight of Xifeng(32.32g)was the largest,while Hequ(11.34 g)was the least;Seed width of Jingyuan(5.32 mm)was the largest,while Xifeng(4.10 mm)was the least;Seed thickness of Jingyuan(3.32 mm)was the largest,while Hequ(2.57mm)was the least;TKW of Jingyuan(5.43 g)was the largest,while Ganquan in Shaanxi(2.94 g)was the least;Vitality(60%),vigour(18.17),germination rate(47%),germination potential(8%),nursery germination rate(23%)of Hequ was the least,while the maximums were different;On the whole,Hequ owned the worst character.(2)Pinus tabulaeformis in different regions can be divided into three levels(high,medium and low)by probability grading.Most characters of Jingyuan in cone and seed were at a high level.Cone length and width of Jingyuan and Huating in Shaanxi were better than Jixian,Huanglong in Shaanxi.Cone length,width,weight,water content and maturity ratio of Jingyuan,and Xifeng were obvious superior to Hequ.Wing length and length,width and thickness of seed in Jingyuan and Huating were superior to Jixian,Huanglong in Shaanxi,Hequ.Germination traits of Huating had an obvious advantage over Jingyuan and Hequ.(3)The overall character information of samples were replaced by the principal component one(cone length,width).To evaluate 10 regional Pinus tabulaeformis seed quality,the measurement result of clustering analysis showed JingYuan characters were the best and Hequ was the worst.(4)There were obvious differences in seedling characters(underground fresh weight,aboveground fresh weight,whole fresh weight,underground dry weigh,above ground dry weight,whole dry weight,ground diameter,seedling height,needle number and needle length).Root length(71.10),surface area(10.80cm2),volume(0.13cm3)of Jing Yuan were significantly higher than other regions.Root of Hequ(358.20)and Xunyi(338.4)were significantly higher than other regions.Membership function method showed Jingyuan was best seedling growth condition,and Huangling was worst related to comprehensive score method.Seedling growth also reflected the local environmental conditions.