腐植酸、蚯蚓粪及蚯蚓蛋白肥料对滨海盐碱土壤的改良效应

为改良滨海盐碱地土壤性状,保证作物良好生长发育,拟通过调控土壤的化学性状(添加腐植酸)、土壤的生物学性状(添加蚯蚓粪、蚯蚓蛋白菌肥)进行盐碱地的改良,采用盆栽试验方法,以玉米为试验材料,做了相关研究。结果表明添加腐植酸、或蚯蚓粪、或菌肥3种物料相对于单施化学肥料都能不同程度地增加玉米幼苗地上部和地下部的生物量及对养分的吸收量,但降低了土壤脲酶和碱性磷酸酶活性;添加腐植酸或蚯蚓粪2个处理的玉米地下部生物量都与单施化学肥料处理分别增加了24.2%和18.2%(P0.05);添加菌肥处理可增加土壤速效养分含量,使碱化度和pH分别下降了9.5%和1.1%(P0.05);添加蚯蚓粪处理使土壤CEC含量增加了3.2%,且能降低土壤中全盐含量;添加腐植酸使有机质提高了4.3%,并降低pH(P0.05);添加菌肥或蚯蚓粪处理可显著增加土壤中的微生物量碳和微生物量氮的含量(P0.05);添加腐植酸、或蚯蚓粪、或菌肥处理的土壤脲酶和碱性磷酸酶活性都低于单施化学肥料处理。因此,在滨海盐碱地上施用化学肥料添加腐植酸、或蚯蚓粪、或菌肥能够改善土壤的性状,促进作物的生长。     

外源一氧化氮供体对感染轮纹病菌后梨质膜H+—ATPase及抗氧化酶活性的影响

梨叶片感染轮纹病菌5d后,用不同浓度的一氧化氮供体硝普钠(SNP)处理,测定了质膜H —ATPase及抗氧化酶活性的变化。结果表明:浓度为0.3mmol/L SNP处理可提高H —ATPase、抗坏血酸过氧化物酶(APX)、愈创木酚过氧化物酶(GPX)和谷胱甘肽还原酶(GR)活性,降低脂氧合酶(LOX)活性;浓度为0.1mmol/L和0.6mmol/L SNP处理则对其影响效果不明显;在同一浓度SNP处理组中,随处理时间的延长,其变化不同,较低浓度的SNP可缓解轮纹病菌对梨的伤害作用。     

Reevaluation of the Phosphorus Requirement of Juvenile Olive Flounder Pavalichfhys olivaceus and the Bioavailability of Various Inorganic Phosphorus Sources

A 6‐wk feeding trial was conducted to reevaluate the phosphorus (P) requirement of juvenile olive flounder and the bioavailability of various inorganic phosphorus sources (IPS). Eight experimental diets were prepared such that all diets contained the same amount of calories, nitrogen, and calcium. Each diet included 0.33% total phosphorus (TP) and 0.60 % total calcium supplied by the basal diet. The eight experimental diets were: the basal diet without P supplementation (BD), three diets consisting of the BD supplemented with NaH,PO₄.2H₂O (NaP_0.45 NaP_0.57 or NaP_1.14) to supply 0.45, 0.57 or 1.14% TP, and four diets consisting of the BD supplemented with K₂HPO₄ (KP_0.57), Ca(H₂PO₄)_;H₂O (Cap_0.57), CaH₂PO_4;2H₂O (CaHP_0.57) or flounder bone meal (FBP_0.57) to supply 0.57% TP. Fish (N = 480)averaging 4.02 ± 0.03 g (Mean ± SD) were distributed randomly into 24 aquaria (20 fish per aquarium), and were fed one of the eight experimental diets in triplicate groups. The weight gain (WG), specific growth rate (SGR), protein efficiency ratio (PER) and feed efficiency (FE) of fish fed the NaP_0.57 diet were significantly higher than those of fish fed the BD, NaP_1.14, KP_0.57, CaHP_0.57 and FBP_0.57 diets (P > 0.05). There was no significant difference in WG, SGR, PER, and FER among fish fed the Nap_0.45, NaP_0.57 and Cap_0.57, diets. Whole body P retention (WBP_ret) in fish fed the Nap_0.57 diet was significantly higher than in fish fed the BD, NaP_1.14, KP_0.57 CaHP_0.57 and FBP_0.57diets (P > 0.05). There was no significant difference in WBP_ret among fish fed the NaP_0.47, NaP_0.57, and CaP_0.57, diets. The ability of the fish to digest the phosphorus in the NaP_0.45, Nap_0.57, NaP_1.14, and CaP_0.57 diets was significantly better than that of fish fed the other diets (P > 0.05). These results indicated that the dietary P requirement for juvenile olive flounder could be 0.45457%. Also, NaH,PO_; 2H₂O and Ca(H₂PO₄)_;H₂O appeared to have a better bioavailability than the other P sources in juvenile olive flounder.     

垄作沟覆地膜对旱地马铃薯光合特性及产量形成的影响

为探讨垄作沟覆不同地膜对旱地马铃薯光合特性及产量形成的影响,于2018—2019年在宁夏南部山区设置垄上覆盖普通塑料地膜,沟内分别覆盖普通塑料地膜(DD)、可降解渗水地膜(DS)和麻纤维地膜(DM),以沟不覆盖为对照(CK),研究其对作物关键生育时期(播后60～120 d)土壤水分、马铃薯功能叶光合特性及产量形成的影响。结果表明,现蕾期(播后60 d)不同覆盖处理可显著提高0～100 cm层土壤贮水量, 2018年以DD处理最高, 2019年以DM处理最高,分别较CK显著提高11.2%和21.6%。马铃薯关键生育时期,除2019年DS处理叶面积指数较CK显著提高外,其他处理间差异均不显著;不同覆盖处理可有效提高净光合速率和蒸腾速率,其中在块茎膨大期(播后120 d) DM处理分别较CK显著提高30.0%和23.2%。2年块茎膨大期DD、DM和DS处理块茎干物质累积量平均分别较CK显著提高54.9%、50.0%和22.6%,马铃薯产量平均分别较CK增产13.2%、14.1%和5.2%,平均净收入分别增收16.3%、14.6%和4.0%,而DS处理马铃薯产量和净收益与CK相比差异均不显著。...     

Association analysis of physicochemical traits on eating quality in rice (Oryza sativa L.)

Improvement of rice eating quality is an important objective in current breeding programs. In this study, 130 rice accessions of diverse origin were genotyped using 170 SSR markers to identify marker–trait associations with physicochemical traits on eating quality. Analysis of population structure revealed four subgroups in the population. Linkage disequilibrium (LD) patterns and distributions are of fundamental importance for genome-wide mapping associations. The mean r ² value for all intrachromosomal loci pairs was 0.0940. LD between linked markers decreased with distance. Marker–trait associations were investigated using the unified mixed-model approach, considering both population structure (Q) and kinship (K). In total, 101 marker–trait associations (p < 0.05) were identified using 52 different SSR markers covering 12 chromosomes. The results suggest that association mapping in rice is a viable alternative to quantitative trait loci mapping, and detection of new marker–trait associations associated with rice eating quality will also provide important information for marker-assisted breeding and functional analysis of rice grain quality.     

Degradation of Organic Compounds in Actual Wastewater by Electro-Fenton Process and Evaluation of Energy Consumption

We investigated the Fe-regeneration-based cathodic electro-Fenton process using commercial electrodes, to achieve reducing the initial Fe dose and consequent sludge accumulation. The obtained results provided insights into the cathodic electro-Fenton process using two-electrode electrochemical system. The grade 2 Ti mesh electrode could effectively regenerate Fe(II) at 1.2 V, whose potential was lower than those of the two other electrode systems reported in the literatures. In the actual wastewater treatment, compared with general-Fenton process, the reduction in the initial Fe injection was 33% and the sludge reduction was 38%. Furthermore, the removal efficiency using electro-Fenton was at least 5% higher than that of the general-Fenton process at the same initial dose. The low cell voltage (1.2 V) led to lower energy consumption (3.5 J mg^?1) relative to those of other electro-Fenton systems, i.e., anodic electro-Fenton and peroxide generation. With its competitive degradation performances, low energy consumption, and reduced initial Fe injection, the present cathodic electro-Fenton process was shown to be a promising route of waste treatment.     

混种密度比例对小麦品种竞争系数的影响

在生态学中,竞争是生物个体利用共享的有限资源发生的相互作用,并导致竞争个体适合度降低的现象,这种现象可以发生在物种之间,也可以发生在物种内部。     

淮北地区麦茬机插优质食味粳稻氮肥减量的精确运筹

当前"减氮"成为优质食味粳稻种植措施之一,但减氮后的氮肥科学运筹方案尚不够明确,需进一步研究。2018—2019年,选用优质食味粳稻品种‘南粳505’和‘南粳2728’为材料,前茬麦秸秆全量还田,采用机插方式,在总施氮量较当地常规施氮量减少20%条件下,设置基蘖肥和穗肥比例分别为5∶5、6∶4、7∶3和8∶2四种氮肥运筹比例,研究了淮北地区麦茬机插优质食味粳稻氮肥减量精确运筹。结果表明,随着基蘖肥占总施氮量比例增加,产量呈先增后降趋势, 7∶3处理产量最高, 2年达11,134.80～11,280.19 kg hm–2,较CK增产1.23%～2.54%,但差异不显著; 7∶3处理群体高产,在于能获得充足的群体颖花量、较高的结实率和千粒重。随着基蘖肥比例增加,有效分蘖临界叶龄期、拔节期群体干物质积累量呈增加趋势;抽穗期、成熟期、抽穗至成熟期的干物质积累量、最终氮素积累量及氮素利用率,呈先增后降趋势,均以7∶3处理最高。与常规施氮处理相比,减氮处理通过增加前期施氮肥比例(7∶3),能确保群体后期获得较高的干物质积累量;成熟期氮素积累量较小,但显著提升了氮素吸收利用率,较CK高14.10%～...     

江淮地区稻–麦周年产量差及其与资源利用关系

江淮地区是我国水稻和小麦重要的生产基地,明确该地区不同产量水平之间的差异特征及形成机制,探索区域粮食生产的限制因子,可为缩减江淮地区周年产量差的技术途径提供科学依据和参考。本研究以稻–麦周年生产体系为研究对象,定量分析不同产量水平田块之间的产量差与气候影响因素。结果表明,江淮地区水稻、小麦及周年农户水平与试验水平和高产纪录间存在显著的产量差,分别为3315.9、1537.5、4645.6 kg hm–2和7498.6、3977.9、9840.9 kg hm^–2。水稻、小麦及周年农户水平较试验水平还有46.2%、29.7%和37.3%的增产潜力,较高产纪录还有104.5%、77.0%和79.0%的增产潜力。每穗粒数是造成水稻产量差的主要因子,穗数和每穗粒数是造成小麦产量差的主要因子。与农户水平相比,水稻试验水平和高产纪录的穗粒数分别增加30.4%和116.1%;小麦试验水平和高产纪录的穗数和每穗粒数平均分别增加40.9%、70.0%和21.8%、19.6%。缩小产量差水稻主要依赖于增加每穗粒数,小麦靠穗数和每穗粒数的协同提高。生育期累积辐射和积温较低是导致水稻产量差异的主要气候因素,而生育期降雨过多是导致小麦产量差异的主要气候因素。根据研究提出了“强稻稳麦”是提升江淮地区周年粮食生产的有效途径。     

Isolation and characterization of 28 polymorphic SSR loci from castor bean (<Emphasis Type="Italic">Ricinus communis</Emphasis> L.)

Castor bean (Ricinus communis) is cultivated for seed oil throughout tropical and subtropical regions but the understanding of its genetic variability is limited. Because applicable microsatellite markers are not sufficient, we isolated and characterized polymorphic simple sequence repeat (SSR) loci acquired from a microsatellite-enriched genomic DNA library of castor bean. Finally, 28 SSR loci revealed polymorphisms in a castor bean collection consisting of 72 accessions. A total of 73 alleles were detected, with an average of 3.18 alleles per locus, and the polymorphism information content (PIC) ranged from 0.03 to 0.47 (mean = 0.26). Values for observed (H_O) and expected (H_E) heterozygosity ranged from 0.00 to 0.19 (mean = 0.11) and from 0.04 to 0.54 (mean = 0.31), respectively. To understand genetic relationships within the castor bean collection, a dendrogram was constructed based on profiles of the 28 SSR loci. These newly developed SSRs will be useful tools for assessing genetic diversity and population structure in castor bean.