[Objective] This study aimed to investigate the effects of different concen- trations of antimony and modifier calcium magnesium phosphate on photosynthetic characteristics of edible amaranth, flowering Chinese cabbag...[Objective] This study aimed to investigate the effects of different concen- trations of antimony and modifier calcium magnesium phosphate on photosynthetic characteristics of edible amaranth, flowering Chinese cabbage, spinach and flowering Chinese cabbage. [Method] By outdoor potting simulation experiment, soil matrixes containing 10.00, 20.00, 50.00, 70.00 and 100.00 mg/kg antimony （Sb3＋） were pre- pared; soil without antimony was used as control （CK）. Each pot was loaded with 0.10 kg/kg vegetable special fertilizer, mixed evenly, and divided into two shares： one share was supplemented with 1.75 g/kg modifier calcium magnesium phosphate and mixed evenly; the other share contained no calcium magnesium phosphate. Af- ter the generation of three true leaves, seedlings with uniform growth were trans- planted into the prepared soil matrixes, eights seedlings per pot. Vegetable seedlings were watered regularly to maintain 70% of field capacity. After 45 d, veg- etable plants were harvested and washed clean with distilled water for measurement of indicators of photosynthetic characteristics. [Result] With the increase of antimony concentration, relative chlorophyll content （SPAD value） and net photosynthetic rate of four vegetable species increased first and then declined, while stomatal conduc- tance of vegetable leaves was linearly reduced. [Conclusion] Appropriately adding modifier calcium magnesium phosphate can effectively improve the photosynthetic characteristics of four vegetable species and reduce the toxic effects of heavy metal antimony on vegetables.展开更多
The phenomenon of cyclic hardening is observed in fatigue tests of modified asphalt controlled by low strain/stress level and it is not clear how the phenomenon affects the fatigue properties of binders. The special t...The phenomenon of cyclic hardening is observed in fatigue tests of modified asphalt controlled by low strain/stress level and it is not clear how the phenomenon affects the fatigue properties of binders. The special time weep tests were performed to investigate the point. Tests results indicate that the cyclic hardening is caused by the rearrangement of molecules in binders, and it can make the inner structure of binders getting stable and increase the fatigue properties of asphalt binders. But fatigue damage occurs when fatigue tests start, no matter the phenomenon of cyclic hardening happens or not. If the controlled load is low, the effect of rearrangement of molecules on material is beyond the effect of fatigue damage so that the cyclic hardening can be observed. When the load conditions get worse, the effect of slight fatigue damages produced in hardening stage will show.展开更多
From the view of methodology for genetic improvement ofJaponicacytoplasmic male sterile(CMS) lines,we introduced the breeding process of the dwarf-abortive type(DA type)JaponicaCMS line Chunjiang 95A with wide compati...From the view of methodology for genetic improvement ofJaponicacytoplasmic male sterile(CMS) lines,we introduced the breeding process of the dwarf-abortive type(DA type)JaponicaCMS line Chunjiang 95A with wide compatibility,and further investigated the biological characteristics of the DA type Chunjiang 95A and its isonuclear alloplasmic CMS line Dian-I type Chunjiang 95A.The results show that DA type Chunjiang 95A is a japonicalinous CMS line and mainly typical abortive,which is better in fertility stability than stained abortive typeJaponica CMS lines.The DA type Chunjiang 95A is featured with high stigma exsertion,good flowering habit,high outcrossing rate and wide compatibility.Its recoverability differs from stained abortive typeJaponicaCMS lines.Moreover,we discussed genetic improvement of the typical abortive type JaponicaCMS lines and the application prospects of heterosis.展开更多
A field experiment was conducted in the Western Highlands of Cameroon to study the effects of Calliandra calothyrsus, sterilized compost, non-sterilized compost and mineral fertilizers （NPK 11：11：22） on physical c...A field experiment was conducted in the Western Highlands of Cameroon to study the effects of Calliandra calothyrsus, sterilized compost, non-sterilized compost and mineral fertilizers （NPK 11：11：22） on physical characteristics, yield components and late blight disease severity of potato （Solanum tuberosum）. A two factorial treatment combination made up of fertilization schemes and sanitary measures were laid out in a randomized complete block design （RCBD） with four replicates and 10 treatments. Data collected were subjected to a multivariate ANOVA and means separated with the Dunnett t-test with Calliandra calothyrsus considered as the main treatment. Mineral fertilizers and Calliandra calothyrsus significantly augmented stem diameter, plant height and plant vigor, total and marketable yields, despite the fact that late blight severity was high in the two treatments. The correlation matrix showed that total yield had significant and positive correlation with stem diameter （r = 0.74）, plant height （r = 0.61）, plant vigor （r = 0.61） and marketable yield （r = 0.99） and negative correlation （r = -37） with late blight severity. The increase observed is attributed to the nutrient contents of the treatments applied. Leafy prunings of C. calothyrsus increase soil organic matter which probably improves moisture retention and biological activity. The highest late blight severity recorded between the 45 and 60 coincides with active development of plant canopy which influences disease severity and create a canopy microclimate conducive to disease development. This study suggests that Calliandra calothyrsus has the potential of improving potato production provided appropriate fungicide is used.展开更多
基金Supported by Fund of Director of Hunan Institute of HorticultureProject for Cultivation Post in Citrus Industry System of Hunan Province(2013)~~
文摘[Objective] This study aimed to investigate the effects of different concen- trations of antimony and modifier calcium magnesium phosphate on photosynthetic characteristics of edible amaranth, flowering Chinese cabbage, spinach and flowering Chinese cabbage. [Method] By outdoor potting simulation experiment, soil matrixes containing 10.00, 20.00, 50.00, 70.00 and 100.00 mg/kg antimony （Sb3＋） were pre- pared; soil without antimony was used as control （CK）. Each pot was loaded with 0.10 kg/kg vegetable special fertilizer, mixed evenly, and divided into two shares： one share was supplemented with 1.75 g/kg modifier calcium magnesium phosphate and mixed evenly; the other share contained no calcium magnesium phosphate. Af- ter the generation of three true leaves, seedlings with uniform growth were trans- planted into the prepared soil matrixes, eights seedlings per pot. Vegetable seedlings were watered regularly to maintain 70% of field capacity. After 45 d, veg- etable plants were harvested and washed clean with distilled water for measurement of indicators of photosynthetic characteristics. [Result] With the increase of antimony concentration, relative chlorophyll content （SPAD value） and net photosynthetic rate of four vegetable species increased first and then declined, while stomatal conduc- tance of vegetable leaves was linearly reduced. [Conclusion] Appropriately adding modifier calcium magnesium phosphate can effectively improve the photosynthetic characteristics of four vegetable species and reduce the toxic effects of heavy metal antimony on vegetables.
文摘The phenomenon of cyclic hardening is observed in fatigue tests of modified asphalt controlled by low strain/stress level and it is not clear how the phenomenon affects the fatigue properties of binders. The special time weep tests were performed to investigate the point. Tests results indicate that the cyclic hardening is caused by the rearrangement of molecules in binders, and it can make the inner structure of binders getting stable and increase the fatigue properties of asphalt binders. But fatigue damage occurs when fatigue tests start, no matter the phenomenon of cyclic hardening happens or not. If the controlled load is low, the effect of rearrangement of molecules on material is beyond the effect of fatigue damage so that the cyclic hardening can be observed. When the load conditions get worse, the effect of slight fatigue damages produced in hardening stage will show.
基金Supported by Key Research Project of Zhejiang Province(2008C22074)0406 Program of Zhejiang Province+2 种基金Fund for theConversion of Agricultural Science and Technology Achievement inZhejiang ProvinceBasic Operation Fund of China National Rice Re-search Institutethe Program of Breeding and Experimental Dem-onstration of Super Hybrid Rice in China from Ministry of Agriculture.
文摘From the view of methodology for genetic improvement ofJaponicacytoplasmic male sterile(CMS) lines,we introduced the breeding process of the dwarf-abortive type(DA type)JaponicaCMS line Chunjiang 95A with wide compatibility,and further investigated the biological characteristics of the DA type Chunjiang 95A and its isonuclear alloplasmic CMS line Dian-I type Chunjiang 95A.The results show that DA type Chunjiang 95A is a japonicalinous CMS line and mainly typical abortive,which is better in fertility stability than stained abortive typeJaponica CMS lines.The DA type Chunjiang 95A is featured with high stigma exsertion,good flowering habit,high outcrossing rate and wide compatibility.Its recoverability differs from stained abortive typeJaponicaCMS lines.Moreover,we discussed genetic improvement of the typical abortive type JaponicaCMS lines and the application prospects of heterosis.
文摘A field experiment was conducted in the Western Highlands of Cameroon to study the effects of Calliandra calothyrsus, sterilized compost, non-sterilized compost and mineral fertilizers （NPK 11：11：22） on physical characteristics, yield components and late blight disease severity of potato （Solanum tuberosum）. A two factorial treatment combination made up of fertilization schemes and sanitary measures were laid out in a randomized complete block design （RCBD） with four replicates and 10 treatments. Data collected were subjected to a multivariate ANOVA and means separated with the Dunnett t-test with Calliandra calothyrsus considered as the main treatment. Mineral fertilizers and Calliandra calothyrsus significantly augmented stem diameter, plant height and plant vigor, total and marketable yields, despite the fact that late blight severity was high in the two treatments. The correlation matrix showed that total yield had significant and positive correlation with stem diameter （r = 0.74）, plant height （r = 0.61）, plant vigor （r = 0.61） and marketable yield （r = 0.99） and negative correlation （r = -37） with late blight severity. The increase observed is attributed to the nutrient contents of the treatments applied. Leafy prunings of C. calothyrsus increase soil organic matter which probably improves moisture retention and biological activity. The highest late blight severity recorded between the 45 and 60 coincides with active development of plant canopy which influences disease severity and create a canopy microclimate conducive to disease development. This study suggests that Calliandra calothyrsus has the potential of improving potato production provided appropriate fungicide is used.
