南疆地区引进苜蓿品种亲缘关系的过氧化物酶分析

[目的]对2012年以来引种试验的20个苜蓿(Medicago)品种的亲缘关系进行研究,为进一步开展南疆苜蓿品种遗传改良、杂交亲本选配提供依据.[方法]以8日龄幼苗和6日龄再生植株为材料,采用过氧化物酶电泳技术对供试品种的亲缘关系进行分析.[结果]20个苜蓿品种幼苗和再生植株材料过氧化物酶的多态位点百分率分别为72.73;和50.00;.供试苜蓿品种间的相似系数介于0.611 ～1.000,平均值为0.815.聚类分析在相似系数为0.776处把供试品种聚为3类,甘农1号单独聚为1类.主成分分析表明,甘农1号在分析图中的位置也相对孤立.[结论]供试苜蓿品种具有一定水平的遗传差异.甘农1号杂花苜蓿与紫花苜蓿品种间亲缘关系较远.与6日龄再生植株材料相比,8日龄幼苗材料的过氧化物酶能更有效地鉴定苜蓿材料的遗传差异.     

Identification of QTL for stalk sugar-related traits in a population of recombinant inbred lines of maize

Increasing sugar content in silage maize stalk improves its forage quality and palatability. The genetic mapping and characterization of quantitative trait loci (QTLs) is considered a valuable tool for trait enhancement, yet little information on QTL for stalk sugar content in maize has been reported. To this end, we investigated QTLs associated with stalk sugar traits including Brix, plant height (PHT), three ear leaves area (TELA), and days to silking (DTS) in two environments using a population of 202 recombinant inbred lines from a cross between YXD053, which has a high stalk sugar content, and Y6-1, which has a low stalk sugar content. A genetic map with 180 SSR and 10 AFLP markers was constructed, which spanned 1,648.6 cM of the maize genome with an average marker distance of 8.68 cM, and QTLs were detected using composite interval mapping. Seven QTLs controlling Brix were mapped on chromosomes 1, 2, 6 and 9 in the combined environments. These QTLs could explain 2.69–13.08 % of the phenotypic variance. One major QTL for Brix on chromosome 2 located between the markers bnlg1909 and umc1635 explained 13.08 % of the phenotypic variance. Y6-1 also contributed QTL allele for increased Brix on chromosome 6. One major QTLs controlling PHT on chromosome 1 and TELA on chromosome 4 were also identified and accounted for 13.68 and 12.49 % of the phenotypic variance, respectively. QTL alleles for increased DTS were located on chromosomes 1 and 5 of YXD053. Significant epistatic effects were identified in four traits, but no significant QTL × environment interactions were observed. The information presented here may be valuable for stalk sugar content improvement via marker-assisted selection in silage maize breeding programs.     

Analysis of genetic effects on a complete diallel cross test of Betula platyphylla

The study utilized the offspring of a 5 × 5 diallel cross of Betula platyphylla as the experimental material. Tree height (H), diameter at breast height (DBH) and stem straight degree (SSD) were measured at the fourth and eighth growth year (SSD were measured only in the eighth growth year). ANOVA analyses showed that growth traits in different growth years were significant among families (P < 0.01). There existed extremely significant correlations between H and DBH in the same year. Although the sequencing of average H and DBH of different families were vicissitudinous at the 4th and 8th year, there also existed significant correlations between H and DBH in different year. The general combining ability, special combining ability (SCA) and reciprocal effect (REC) of different hybridized combinations were also different remarkably. The mean square of SCA was significantly higher than GCA, implied that the non-additive effect played major roles. When B5, B8 and MB15 were selected as parents, the offspring performed perfectly in traits of H, DBH and SSD at the eighth growth year respectively. B5 × XB11, B8 × XB11 and B8 × MB15 had highest SCA values in traits of H, DBH, and SSD at the eighth growth year respectively. Consequently, in order to achieve optimal outcomes, seed orchard building and clonal propagation should be considered simultaneously in birch’s genetic improvement process.     

防治眼菌蚊Bt.菌株的筛选与培养条件优化

通过11株Bt.菌株对平菇厉眼蕈蚊3龄幼虫的室内毒力测定试验,得出91019菌株对平菇厉眼蕈蚊3龄幼虫有较高的毒力效果,其发酵原液和250倍稀释液对平菇厉眼蕈蚊3龄幼虫的校正死亡率分别达到93.10%和82.76%。通过正交试验对91019菌株的各培养条件进行优化,得出理论最佳培养基组分及培养条件为:玉米粉1.0%、黄豆饼粉2.5%、酵母粉2.0%、鱼粉2.0%、蛋白胨0.4%,KH2PO4 0.5 g/L,CaCO3 4.0 g/L,MgSO4.7H2O0.5 g/L,ZnSO4.7H2O 0.02 g/L;接种量2.0%、pH7.0、装液量25 mL、培养温度25℃。     

春小麦不同品种籽粒蛋白质和干物质动态变化研究

[目的]研究春小麦不同品种籽粒灌浆过程中蛋白质和粒重的积累动态,为新疆春小麦优质高产种植提供理论依据.[方法]采用杜马斯燃烧法测定不同灌浆时期籽粒粗蛋白含量.[结果]春小麦不同品种在籽粒灌浆过程中蛋白质含量的变化动态及累积趋势是基本一致的,呈高、低、高的"V"型变化规律.粒重在灌浆前期增长迅速,后期增大缓慢;不同品种之间籽粒蛋白质含量积累变化动态存在差异,灌浆前期籽粒蛋白质含量与成熟期籽粒蛋白质含量关系不明显.[结论]蛋白质含量高的品种其含量增加主要在灌浆中后期;不同品种籽粒产量和蛋白质产量同步增加,籽粒蛋白质含量与千粒重间呈有负相关关系.     

长期定位施肥对设施黄瓜肥料利用率的影响

通过8a来对8个不同施肥方式进行定位试验,研究了大棚黄瓜对氮磷钾肥的当季利用率和累积利用率。试验结果表明,在施氮量相同的情况下,常量施用有机肥配合化肥的处理黄瓜肥料利用率最高,氮、磷、钾利用率分别为63.2%,28.5%,53.6%。氮肥利用率大小顺序为：MNPK〉NPK〉NK〉1.5MNPK〉N〉NP。养分不均衡处理N、NK、PK对肥料的利用率均很低。磷肥的当季利用率要小于氮肥,但前5a有一定的累加效应。磷肥利用率大小顺序为MNPK〉NPK〉1.5MNPK〉NP〉PK。钾肥利用率大小顺序为MNPK〉1.5MNPK〉NPK〉NP〉NK。肥料用量愈大,肥料利用率愈低,MNPK处理的肥料使用量是1.5MNPK处理的67%,而该处理的N、P、K的平均当季利用率分别是1.5MNPK处理的1.8倍、1.9倍、1.2倍。     

Nitrogen efficiency in long-term wheat–maize cropping systems under diverse field sites in China

Efficiency of fertilizer N is becoming increasingly important in modern agricultural production owing to increasing food requirement and growing concern about environments. However, there is almost no study regarding its long-term efficiency in wheat and maize cropping systems. Long-term (15 years) experiments involving wheat (Triticum aestivum L.) and maize (Zea mays L.) rotations at five field sites with various soil and climate characteristics in China were used to determine the nitrogen (N) efficiency, including the physiological efficiency, recovery efficiency and N mass balance of soil–plant systems in response to different fertilization treatments. The present study consisted of nine treatments: unfertilized, N, phosphorus, potassium, straw and manure or their combinations. The contribution of N fertilizers to wheat yield was higher than to maize and suggested that wheat could be given priority over maize when determining N application rates. Uptake of 1 kg N produced 35.6 kg of wheat grain and 39.5 kg of maize grain. The deficit of N in soils without applied N ranged from 40 to 103 kg N ha⁻¹ year⁻¹, while N surpluses in soils with applied N fertilizers ranged from 35 to 350 kg N ha⁻¹ year⁻¹. The apparent accumulated N recovery efficiency (NRE_ac) varied widely from 4% to 90%: unbalanced fertilization and other soil limiting factors (such as aluminium toxicity) were associated with low NRE_ac. In the treatments of combination of N, phosphorus and potassium with normal application rates, the average of NRE_ac in four out of five sites reached 80%, which suggested that best management of N fertilizers could recover most of N fertilizers applied to soils. The results will be helpful to understand the long-term fate of N fertilizers and to optimize the N fertilization for agricultural practices and environment protection.     

天津市静海县早春西瓜双膜覆盖栽培技术

介绍由天津市静海县农技人员结合实践经验总结形成的早春西瓜双膜覆盖栽培技术,以期为静海地区广大瓜农规范应用相关的技术提供数据支持。早春西瓜双膜覆盖栽培模式生产效益较高,达到1 600元/667 m2以上,且易于操作,生产投入成本较低,为广大瓜农所接受,目前全县推广面积达到1 300 hm2。     

下辽河平原典型区域耕地利用变化及保护开发途径研究

本研究采用统计分析与遥感判读相结合的方法,对下辽河平原区典型区域耕地利用变化进行研究.结果表明:耕地是研究区域主要土地利用类型,耕地分布比较集中,总体分布不均衡,其中生态退耕、建设用地占用、灾毁和农业产业结构调整是耕地减少的主要原因,对于林地的开垦、未利用土地开发、居民点及工矿用地和水利设施用地整理是耕地增加的主要来源,但耕地总体是逐年减少的.本文提出要处理好耕地保护与粮食安全、城市发展和生态环境建设之间的关系,具体可以通过提高耕地质量保证粮食安全;通过建立城乡统一的土地市场,协调城市化和耕地减少之间的矛盾;通过合理的生态退耕,协调生态环境建设与耕地保护之间的关系.     

两种砧木对布鲁克斯大樱桃果实芳香成分的影响

【研究目的】为研究考特和吉塞拉作为砧木对甜樱桃果实香气成分的影响。【方法】采用顶空微萃取技术提取成熟期果实的香气成分,经气相色谱质谱联用仪进行测定分析。【结果】不鲁克斯甜樱桃的香气成分共检测到61种,主要成分为醛类、醇类和酯类。从布鲁克斯（吉塞拉）中检测出38种香气成分占总峰面积的59.66 %,相对百分含量较高的是乙醇、乙酸己酯、1-乙基－3－甲基苯、苯乙烯、1,2,3－三甲基苯。从布鲁克斯（考特）中检测出30种香气成分占总峰面积的64.74 %,相对百分含量较高的是乙醇、（E)2－己烯－1－醇、3-异丁基-6-烯-1-辛醇、乙酸己酯。【结论】吉塞拉和考特作为砧木对布鲁克斯甜樱桃果实中香气成分的影响较明显,在香气种类上吉塞拉砧木具有明显优势。（E)2－己烯－1－醇、己醛、乙酸己酯、(E)-丁酸－2－己烯酯、3-异丁基-6-烯-1-辛醇是不鲁克斯甜樱桃成熟果实的特征香气成分。