The microfibril angle of seven poplar clones was determined by using X-ray diffraction technique. Microfibril angle, wood basic density, fiber length, fiber width and cellulose content were assessed for every growth r...The microfibril angle of seven poplar clones was determined by using X-ray diffraction technique. Microfibril angle, wood basic density, fiber length, fiber width and cellulose content were assessed for every growth ring at breast height for all sample trees. Significant variation in microfibril angle was observed among growth rings. Mean microfibril angle (MFA) at breast height varied from 7.8?to 28?between growth rings with cambial age and showed a consistent pith-to-bark trend of decline an-gles. Analysis of variance also indicated that there were significant differences in wood basic density, fiber length, fiber width and cellulose content between the growth rings, which had an increasing tendency from pith to bark. Correlations between MFA and examined wood properties were predominantly large and significant negative (?0.01), and the coefficients were -0.660 for cellulose content, -0.586 for fiber length, -0.516 for fiber width and -0.450 for wood basic density, respectively. Regression analysis with linear and curve estimation indicated that a quadratic function showed the largest R2 and the least standard error for describing the relationships between microfibril angle and measured wood properties, and the correlation coefficients were over -0.45 (n=125). The results from this study suggested that microfibril angle would be a good characteristic for improvement in the future breeding program of poplars.展开更多
[ Objective] This study was to breed rice cultivars with multi-resistance to Orseolia oryzae （Wood-Mason）. [ Method] The Guangxi local cultivar GX-M001 （Jiangchao） with high resistance to Orseolia oryzae （Wood-Ma...[ Objective] This study was to breed rice cultivars with multi-resistance to Orseolia oryzae （Wood-Mason）. [ Method] The Guangxi local cultivar GX-M001 （Jiangchao） with high resistance to Orseolia oryzae （Wood-Mason） was used to hybrid with the known resistance cultivars ＂Kangwenqingzhan＂ （harboring GM5 gene）, OB677（ harboring GM3 gene） from Sri Lanka, HT1350 and high yield end quality cultivar ＂ Guiruanzhan＂. [ Result] Through pyramiding the multi-resistant genes via routine hybridization, the general resistances of the hybrids were remarkably enhanced. The grades of resistance were also improved, many of the combinations were endowed with a resistance at immune level （grade 0） ; and interestingly, the respective hybridization of GX-M001 （high resistance） with OB677（ medium resistance） and HT1350（suscepti- ble） also generate two lines at immune level, which is probably the effects of additive effects of genes.[ Conclusion] By routine hybridization, multiple genes were successfully pyramided, thus generating novel rice lines with multiple resistances. For the rice breeding scientists at the grass-roots level, the resistance-resistance pyramiding is an effective approach to breed high resistance cultivars.展开更多
[Objective] The aim was to research the genetic mechanism of barley male sterility, and provide the theoretical reference for breeding strong heterosis hybrid of barley. [ Method] Fertility segregation phenomenon, mor...[Objective] The aim was to research the genetic mechanism of barley male sterility, and provide the theoretical reference for breeding strong heterosis hybrid of barley. [ Method] Fertility segregation phenomenon, morphological characteristics and main agronomic characters of male sterility character of 4 kinds of barley male sterility materials 2001 - 17, 2001 - 37, 2001 - 84 and 2001 - 116 and their dedved lines were observed and researched.[ Result] Barley male sterility existed genetic phenomenon of single dominant nuclear gene caused by environmental stimulation, its sterility controlled by MS, the sterile genotype was MSms. There was stable nucleo-cytoplasmic inheritance on barley male sterility which was controlled by cytoplasmic mate sterile gene S and nuclear gene rr, and its genotype was S（rr）, this male sterility belonged to CMS type sterility. Temperature had no effect on fertility. [ Conclusion] There was stable nucleo-cytoplasmic inheritance on barley male sterility, this result played a positively promoting role in barley practical production.展开更多
To further increase millet yield, the ideal plant in millet has become the goal of high yield breeding for millet. Taking crossbreeding or dynamic breeding technique as dominant and technologies such as modern selecti...To further increase millet yield, the ideal plant in millet has become the goal of high yield breeding for millet. Taking crossbreeding or dynamic breeding technique as dominant and technologies such as modern selection or system selection as subsidiary, progenies with ideal plant are selected by using new germplasms such as Lilvgu and Lizigu with the significant difference in plant type to other cultivars as parents. The ge- netic characteristics of new germplasms in breeding are also emphatically analyzed to summarize the breeding experience of ideal plant, which has been proved that the combination of ideal plant and heterosis utilization is one of the important ways to raise millet yield breakthrough.展开更多
With the deep researches on male sterility genetic engineering of plants, several strategies creating male sterile materials have been developed, such as causing pollen abortion by cytotoxic genes, antisense RNA or RN...With the deep researches on male sterility genetic engineering of plants, several strategies creating male sterile materials have been developed, such as causing pollen abortion by cytotoxic genes, antisense RNA or RNAi silencing the expression of genes related to pollen development, early degradation of tapetum callose leading to male sterility. Male sterile transgenic plants can be obtained through genetic transformation with related genes destroying or interfering with pollen or anther development. Male sterile cauliflower, tomato, cabbage, etc. have been developed in this way, and some begin to be used to produce hybrid seed. Appling some techniques can also maintain and restore the male sterility. These related researches will effectively promote the heterosis utilization and the development of crop breeding. This paper mainly presents their principles and applications in vegetable crops.展开更多
基金This research was supported by National Natural Science Foundation of China (Grant No. 30070616).
文摘The microfibril angle of seven poplar clones was determined by using X-ray diffraction technique. Microfibril angle, wood basic density, fiber length, fiber width and cellulose content were assessed for every growth ring at breast height for all sample trees. Significant variation in microfibril angle was observed among growth rings. Mean microfibril angle (MFA) at breast height varied from 7.8?to 28?between growth rings with cambial age and showed a consistent pith-to-bark trend of decline an-gles. Analysis of variance also indicated that there were significant differences in wood basic density, fiber length, fiber width and cellulose content between the growth rings, which had an increasing tendency from pith to bark. Correlations between MFA and examined wood properties were predominantly large and significant negative (?0.01), and the coefficients were -0.660 for cellulose content, -0.586 for fiber length, -0.516 for fiber width and -0.450 for wood basic density, respectively. Regression analysis with linear and curve estimation indicated that a quadratic function showed the largest R2 and the least standard error for describing the relationships between microfibril angle and measured wood properties, and the correlation coefficients were over -0.45 (n=125). The results from this study suggested that microfibril angle would be a good characteristic for improvement in the future breeding program of poplars.
基金Supported by National Natural Science Foundation of China(30760117)National Key Technology R &D Program (2007BAD68B01)~~
文摘[ Objective] This study was to breed rice cultivars with multi-resistance to Orseolia oryzae （Wood-Mason）. [ Method] The Guangxi local cultivar GX-M001 （Jiangchao） with high resistance to Orseolia oryzae （Wood-Mason） was used to hybrid with the known resistance cultivars ＂Kangwenqingzhan＂ （harboring GM5 gene）, OB677（ harboring GM3 gene） from Sri Lanka, HT1350 and high yield end quality cultivar ＂ Guiruanzhan＂. [ Result] Through pyramiding the multi-resistant genes via routine hybridization, the general resistances of the hybrids were remarkably enhanced. The grades of resistance were also improved, many of the combinations were endowed with a resistance at immune level （grade 0） ; and interestingly, the respective hybridization of GX-M001 （high resistance） with OB677（ medium resistance） and HT1350（suscepti- ble） also generate two lines at immune level, which is probably the effects of additive effects of genes.[ Conclusion] By routine hybridization, multiple genes were successfully pyramided, thus generating novel rice lines with multiple resistances. For the rice breeding scientists at the grass-roots level, the resistance-resistance pyramiding is an effective approach to breed high resistance cultivars.
基金Supported by National Natural Science Foundation of Inner Mongolia(200711020307)Public Industry ( Agriculture)Specific Re-search Program of Ministry of Agriculture (nyhyzx07-010)~~
文摘[Objective] The aim was to research the genetic mechanism of barley male sterility, and provide the theoretical reference for breeding strong heterosis hybrid of barley. [ Method] Fertility segregation phenomenon, morphological characteristics and main agronomic characters of male sterility character of 4 kinds of barley male sterility materials 2001 - 17, 2001 - 37, 2001 - 84 and 2001 - 116 and their dedved lines were observed and researched.[ Result] Barley male sterility existed genetic phenomenon of single dominant nuclear gene caused by environmental stimulation, its sterility controlled by MS, the sterile genotype was MSms. There was stable nucleo-cytoplasmic inheritance on barley male sterility which was controlled by cytoplasmic mate sterile gene S and nuclear gene rr, and its genotype was S（rr）, this male sterility belonged to CMS type sterility. Temperature had no effect on fertility. [ Conclusion] There was stable nucleo-cytoplasmic inheritance on barley male sterility, this result played a positively promoting role in barley practical production.
基金Supported by the "Eleventh Five-Year "National Science and Tech-nology Supporting Plan(2006BAD02B02-01-02)National Modern Millet Industry System Fund~~
文摘To further increase millet yield, the ideal plant in millet has become the goal of high yield breeding for millet. Taking crossbreeding or dynamic breeding technique as dominant and technologies such as modern selection or system selection as subsidiary, progenies with ideal plant are selected by using new germplasms such as Lilvgu and Lizigu with the significant difference in plant type to other cultivars as parents. The ge- netic characteristics of new germplasms in breeding are also emphatically analyzed to summarize the breeding experience of ideal plant, which has been proved that the combination of ideal plant and heterosis utilization is one of the important ways to raise millet yield breakthrough.
文摘With the deep researches on male sterility genetic engineering of plants, several strategies creating male sterile materials have been developed, such as causing pollen abortion by cytotoxic genes, antisense RNA or RNAi silencing the expression of genes related to pollen development, early degradation of tapetum callose leading to male sterility. Male sterile transgenic plants can be obtained through genetic transformation with related genes destroying or interfering with pollen or anther development. Male sterile cauliflower, tomato, cabbage, etc. have been developed in this way, and some begin to be used to produce hybrid seed. Appling some techniques can also maintain and restore the male sterility. These related researches will effectively promote the heterosis utilization and the development of crop breeding. This paper mainly presents their principles and applications in vegetable crops.
