Why high grain yield can be achieved in single seedling machine-transplanted hybrid rice under dense planting conditions?     

HUANG Min  SHAN Shuang-lü  XIE Xiao-bing  CAO Fang-bo  ZOU Ying-bin 《农业科学学报》2018,17(6):1299-1306

This study was conducted to identify the factors associated with high grain yield in single seedling machine-transplanted hybrid rice under dense planting conditions. Field experiments were done in Yong'an Town, Hunan Province, China in 2015 and 2016. Two hybrid rice cultivars were grown under single seedling machine transplanting (SMT) and conventional machine transplanting (CMT) at a high planting density in each year. Grain yield and yield attributes were compared between SMT and CMT. Averaged across cultivars and years, grain yield was 12% higher under SMT than under CMT. Plant height, basal stem width, and shoot and root dry weights were higher in seedlings for SMT than those for CMT. SMT had less maximum tiller number per m² and consequently less panicle number per m² than did CMT. Branch number per panicle, especially the secondary branch number per panicle, and spikelet number per cm of panicle length were more under SMT than under CMT, which resulted in more spikelet number per panicle under SMT than under CMT. SMT had higher or equal spikelet filling percentage than did CMT. The difference in grain weight between SMT and CMT was relatively small and inconsistent cross years. SMT had higher or equal total biomass and harvest index than did CMT. Dry weight per stem under SMT was heavier than that under CMT. Larger leaf area per stem was partly responsible for the heavier dry weight per stem under SMT than under CMT. Our study suggests that improvement in seedling quality, panicle size, and dry weight per stem are critical to the high grain yield in single seedling machine-transplanted hybrid rice under dense planting conditions.  相似文献   

巨菌草高温快速干燥设备设计与试验   总被引：1，自引：0，他引：1  

孙庆运  王光辉  王德成  李岩芳  叶炳南 《农业机械学报》2018,49(9):338-345

为了解决巨菌草含水率高、不易贮藏,以及自然晾晒中人工劳动强度大、营养损失大的问题,设计了一套大型高秆禾草高温快速干燥设备。基于传热传质理论,进行了关键参数计算与关键部件的设计,通过力学分析与FLUENT流体仿真进行优化,并对控制单元进行了设计。以最终含水率、水活度、色泽度、粗蛋白含量、酸性洗涤纤维含量和中性洗涤纤维含量为评价指标,进行了设备的干燥试验,并与新鲜物料、自然晾晒干燥进行对比分析。结果表明:高温快速干燥后,巨菌草的最终含水率为(16±1.82)%,水活度为0.564 8,生产率为2.73 t/h;与新鲜物料相比,亮度值L和蓝黄值b均无显著性差异,红绿值a增加了1.43;粗蛋白含量与酸洗中洗纤维含量均无显著性变化,粗蛋白质量分数较新鲜物料下降0.6个百分点。与自然晾晒相比,高温快速干燥后巨菌草的粗蛋白质量分数增加了0.63个百分点,且具有较好的表观质量。试验结果表明,该套设备改善了干燥后巨菌草的表观质量和品质,满足了巨菌草干燥的要求。  相似文献   

Gonadal sex differentiation in hybrid snakehead of Channa argus (♂)  × Channa maculate (♀)          下载免费PDF全文

Aiguo Zhou  Shaolin Xie  Zhenlu Wang  Yanfeng Chen  Lanfen Fan  Chao Wang  Meifang Wang  Jixing Zou 《Aquaculture Research》2018,49(6):2345-2348

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Local and scientific knowledge to assess plot quality in Central Spain   总被引：1，自引：0，他引：1  

Celia Barbero-Sierra  Manuel Ruíz Pérez  María José Marqués Pérez  Ana María Álvarez González  José Luis Cruz Maceín 《Arid Land Research and Management》2018,32(1):111-129

Farmers’ land management is a key factor for sustainable agriculture, yet the traditional knowledge which constitutes its base is seldom incorporated in the land and soil academic literature. The need for a hybrid approach that combines local (farmers’) and scientific knowledge is formally recognized. Plot quality criteria are a component of both sources of knowledge, playing an important role in shaping land management practices. Yet there are few case studies comparing the criteria used by farmers and soil scientists when assessing plot quality, particularly in developed countries. We compare the plot quality assessment done by a sample of 31 farmers in a semiarid area of Spain with an edaphic quality index (EQI) obtained through laboratory analyses of soil samples from 61 farm plots. There is a coincidence between farmer and laboratory assessments in 70% of cases. Plots identified by farmers as being of good quality have a significantly higher EQI than those identified as bad quality. The two key differentiating parameters were clay content (average 21% in good versus 18% in bad quality plots) and soil organic carbon content (1.6 and 1.3%, respectively), both closely related to soil water retention ability. A holistic land vision, a higher level of education and large differences in EQI between good and bad plots as assessed by farmers have a positive influence in the degree of coincidence between farmers’ and laboratory assessments.  相似文献   

Fishmeal replacement by soybean,rapeseed and cottonseed meals in hybrid sturgeon Acipenser baerii ♀ × Acipenser schrenckii ♂          下载免费PDF全文

H.‐B. Jiang  L.‐Q. Chen  J.‐G. Qin 《Aquaculture Nutrition》2018,24(4):1369-1377

A 12‐week feeding trial was conducted to evaluate the effects of replacing fishmeal (FM) with soybean meal (SBM), rapeseed meal (RM) and cottonseed meal (CSM) on growth, feed utilization and body composition of juvenile hybrid sturgeon Acipenser baerii ♀ × Acipenser schrenckii ♂ (initial body weight, 8.63 ± 0.24 g). Five isonitrogenous and isoenergetic diets were formulated as follows: a control diet (FM60) containing 600 g/kg FM and four other diets (FM45, FM30, FM15 and FM0 containing 450, 300, 150 and 0 g/kg FM, respectively) where protein from FM was substituted by a mixture of SBM, RM and CSM. Fish fed FM0 and FM15 had poorer growth performance, feed utilization, apparent digestibility coefficients of dry matter, protein, lipid and gross energy, and fed FM0 had poorer hepatosomatic index and survival compared with the fish fed FM60. The whole body lipid in fish fed FM0 was significantly higher than that in fish fed FM60 and FM15. This study indicates that 300 g/kg of FM can be replaced with a mixture of SBM, RM and CSM in the diet of juvenile hybrid sturgeon without compromising growth performance, feed utilization and body composition.  相似文献   

早熟厚皮甜瓜新品种‘佳蜜脆’     

孙春青  马志虎  孙国胜  张振超  戴忠良 《园艺学报》2018,45(8):1627-1628

‘佳蜜脆’是优质早熟厚皮甜瓜杂交一代新品种。植株长势较强,果实近圆形,单瓜质量1.6 kg,果皮黄色,果肉浅橙色,肉质脆,肉厚4.1 cm,中心糖含量13.6%,边糖含量9.1%,折合产量33.5 t · hm-2。适宜在江苏南部地区早春保护地栽培。  相似文献   

辣椒新品种‘新科18号’     

郭志伟  李贞霞  任福森  陈昊放 《园艺学报》2018,45(8):1623-1624

‘新科18号’是利用雄性不育系‘161A’为母本,恢复系‘07-199’为父本,培育的三系杂交辣椒新品种。果实羊角形,纵径22.3 cm,横径3.7 cm,肉厚0.34 cm,平均单果质量76.9 g;果实表面光滑,黄绿色,味微辣,皮薄、质脆,口感极佳,鲜果维生素C含量0.911 mg · g-1,平均产量56 590 kg · hm-2,适合早春保护地设施栽培。  相似文献   

四倍体杂交冰草SRAP和SSR分子标记遗传连锁图谱构建     

杨东升  于卓  于肖夏  李晓宇  吴国芳  石悦  张明飞 《麦类作物学报》2018,(8):941-948

为了给后期冰草抗旱耐寒基因筛选及QTL图位克隆搭建平台,并为产量及相关性状QTL定位和分子标记辅助育种奠定基础,以航道冰草和蒙古冰草为亲本,杂交加倍后随机选取180个F₂分离单株为作图群体,利用SRAP和SSR分子标记进行四倍体杂交冰草遗传连锁图谱的构建。结果表明,构建的图谱包含475个标记（240个SRAP标记和235个SSR标记）,分布于14个连锁群,图谱全长为1 592.7 cM,标记间平均间距为3.35 cM,各连锁群长度范围为67.6~145.2 cM。该图谱密度较高、标记位点分布均匀且连锁群更加饱满。  相似文献   

籼粳杂交稻与常规粳稻产量、干物质氮素累积转运及氮素利用差异研究   总被引：2，自引：0，他引：2  

陈贵  陈梅  张红梅  王士磊  施卫明  程旺大 《浙江农业学报》2018,30(12):1992

在相应栽培密度下,通过田间试验研究了浙江省主栽籼粳杂交水稻(甬优12和嘉优中科6号)和常规粳稻(秀水134)的个体和单位面积群体产量、产量构成,及其对氮肥施用的响应特性,同时对其干物质和氮素的累积、转运特性,以及氮素利用效率开展研究。结果表明:甬优12和嘉优中科6号的个体、单位面积群体及日产量均高于秀水134,其中,个体产量优势更明显。尽管籼粳杂交稻单位面积穗数和结实率相对较低,但其穗大粒多。随施氮量增加,甬优12和嘉优中科6号产量呈增加趋势,而秀水134产量在施氮量超过200 kg·hm^-2后即呈下降趋势。甬优12和嘉优中科6号个体和单位面积群体的干物质和氮素累积均高于秀水134,其中个体差异更明显。整体而言,甬优12和嘉优中科6号单位面积群体齐穗期后干物质和氮素转运量较少,转运效率较低。甬优12和嘉优中科6号的氮素利用效率高于秀水134,然而主要表现为氮素吸收效率高,生理利用效率差异不明显。由此可见,籼粳杂交稻的干物质形成和氮素吸收能力高于常规粳稻,但转运量和转运效率较低。另外,与氮素吸收效率相比,籼粳杂交稻的氮素生理利用效率仍有待进一步提高。  相似文献   

水稻重离子诱变早熟突变体M85S特征特性及配合力遗传力分析     

林鑫  吴林宣  陈志强  王慧  刘永柱  肖武名  黄明 《广东农业科学》2018,45(8):1-8

为了利用水稻光温敏核不育系重离子诱变早熟突变体M85S的潜在育种价值,对水稻光温敏核不育系早熟突变体M85S的特征特性及其所配组的F_1代产量构成性状体现的配合力及遗传力进行分析。利用2个光温敏水稻不育系和8个恢复系按2×8不完全双列杂交(NCⅡ)设计配组,对亲本配合力及遗传力进行分析,结果表明,12个农艺性状及产量相关性状区组间差异不显著,组合间差异极显著,说明组合间存在真实的遗传差异,12个性状的遗传受基因加性效应和非加性效应的共同影响,遗传关系复杂。M85S播始历期一般配合力的相对效应值为负值(-2.40%),单株产量一般配合力的相对效应值为正(0.18%),表现为正效应。播始历期、有效穗数、一次枝梗数、穗长、千粒重和粒长的群体一般配合力方差占绝对高的比例,基因的遗传效应占主导作用;株高、总粒数、实粒数和单株产量的群体特殊配合力方差占绝对高的比例,环境效应占主导作用。12个性状的广义遗传力从大到小依次为:粒长播始历期千粒重总粒数穗长实粒数粒宽一次枝梗数有效穗数单株产量结实率株高。综合两个条件,在试验中所组配的16个杂交F_1代中,根据各性状的特殊配合力与一般配合力可知,M85S/创香5号与M85S/航恢1179两个组合较符合早熟与丰产的要求,可见M85S是水稻育种中具有较高应用价值的早熟种质资源,可从遗传上间接协调早熟与丰产矛盾。  相似文献