Normal experiment methods and electron microscope scanning technique were used to compare the differences of the seed morphological characteristics and microstructure of the seed coats between Pinus sibirica and P. ko...Normal experiment methods and electron microscope scanning technique were used to compare the differences of the seed morphological characteristics and microstructure of the seed coats between Pinus sibirica and P. koraiensis . The purpose of this study is to clarify the dormancy and germination characteristics and mechanism of the seeds of P. sibirica. The results showed that the thousand\|grain weight of the measured seeds of P. sibirica was only 39 9% and 48 5% of that of P. koraiensis. The weight of outer seed coats of P. sibirica was 54 04% and 52 6% of their whole seed weight, which was lighter than that of P. koraiensis, while the weight of the seed coat of P. koraiensis was of 61 7% of their whole seed weight. Five layers were seen at the cross section of the hard seed coat of P. koraiensis under scanning electron microscope: external seed epidermis layer (external seed coat), epidermis layer, dense lithocyte layer, palisade layer and inner epidermis. There were four layers in the seed coat of P. sibirica : the external epidermis layer, epidermis layer, palisade layer, and inner epidermis. Thickness of outer seed coat of P. sibirica and P. koraiensis was 400 μm and 1 200～1 300 μm respectively. All these characteristics showed a big hindrance and the permeability barrier in the seed coat of P. sibirica, but not stronger than that of P. koraiensis.展开更多
By the methods of morphological anatomy and investigation in the sample fields, the main studies were carried out such as morphological anatomy of reproductive organs, birch population’s reproductive ages, reproducti...By the methods of morphological anatomy and investigation in the sample fields, the main studies were carried out such as morphological anatomy of reproductive organs, birch population’s reproductive ages, reproductive allotment value and seed behavior. The relationship between birch population and their surroundings was studied. The results showed that birch’s flower organs and its seeds were suitable well for spreading by wind. The seeds by wind can fly far away in a short time. The quantity of seed spreading greatly varied with different communities. Birch’s reproduction age can be changed in different ecological surroundings. The reproductive allotment value of birch was obviously different at different reproductive stages. In the mesic habitat, birch can grow well. The lowest reproductive age of them was 12, average age 15. In most cases the age of branches to bearing fruits was more than 18. The order of reproductive allotment values was as follows: a flowering phase > flower bud phase > fruit phase.展开更多
文摘Normal experiment methods and electron microscope scanning technique were used to compare the differences of the seed morphological characteristics and microstructure of the seed coats between Pinus sibirica and P. koraiensis . The purpose of this study is to clarify the dormancy and germination characteristics and mechanism of the seeds of P. sibirica. The results showed that the thousand\|grain weight of the measured seeds of P. sibirica was only 39 9% and 48 5% of that of P. koraiensis. The weight of outer seed coats of P. sibirica was 54 04% and 52 6% of their whole seed weight, which was lighter than that of P. koraiensis, while the weight of the seed coat of P. koraiensis was of 61 7% of their whole seed weight. Five layers were seen at the cross section of the hard seed coat of P. koraiensis under scanning electron microscope: external seed epidermis layer (external seed coat), epidermis layer, dense lithocyte layer, palisade layer and inner epidermis. There were four layers in the seed coat of P. sibirica : the external epidermis layer, epidermis layer, palisade layer, and inner epidermis. Thickness of outer seed coat of P. sibirica and P. koraiensis was 400 μm and 1 200～1 300 μm respectively. All these characteristics showed a big hindrance and the permeability barrier in the seed coat of P. sibirica, but not stronger than that of P. koraiensis.
文摘By the methods of morphological anatomy and investigation in the sample fields, the main studies were carried out such as morphological anatomy of reproductive organs, birch population’s reproductive ages, reproductive allotment value and seed behavior. The relationship between birch population and their surroundings was studied. The results showed that birch’s flower organs and its seeds were suitable well for spreading by wind. The seeds by wind can fly far away in a short time. The quantity of seed spreading greatly varied with different communities. Birch’s reproduction age can be changed in different ecological surroundings. The reproductive allotment value of birch was obviously different at different reproductive stages. In the mesic habitat, birch can grow well. The lowest reproductive age of them was 12, average age 15. In most cases the age of branches to bearing fruits was more than 18. The order of reproductive allotment values was as follows: a flowering phase > flower bud phase > fruit phase.
