不同营养水平对滩×寒杂种母羊繁殖性能的影响

为研究妊娠后期(97~150 d)、泌乳期(30 d)、催情期(断奶至第2个情期)0.8×NRC(Ⅰ)、0.9×NRC(Ⅱ)和1.0×NRC(Ⅲ)代谢能(metabolic energy,ME)与粗蛋白(crude protein,CP)水平对母羊繁殖性能的影响。将30只1~2胎的滩×寒杂种妊娠母羊随机分成3组(统计的母羊数依次为6,5和7只),单栏饲养。结果表明,1)Ⅰ组母羊产后体重(43.50±7.50 kg)低于Ⅱ(47.20±2.12 kg,P＞0.05)、Ⅲ组(54.79±6.72 kg,P＜0.05),Ⅱ组呈低于Ⅲ的趋势;Ⅲ组母羊自身日增重(137.4±59.8 g)极显著高于Ⅰ、Ⅱ组(-57.7±39.9,34.2±56.2,P＜0.01),Ⅱ也显著高于Ⅰ组(P＜0.05)。各组羔羊初生重(3.82±0.76,3.86±0.58和4.10±0.77 kg)相近(P＞0.05);Ⅲ组的羔羊初生窝重(7.69±2.24 kg)高于(P=0.086)Ⅰ、Ⅱ组(5.73±1.34,5.40±1.65 kg),与其多羔率高有关。2)在泌乳期,母羊泌乳量(27.08±4.52,40.34±11.90,55.48±14.29 kg)、羔羊断奶窝重(13.49±3.82,14.62±3.64,19.32±4.45 kg)、窝增重(7.17±2.71,9.22±2.17,12.28±3.15 kg)、羔羊断奶均重(7.71±2.26,10.45±1.72,11.19±2.51 kg)和增重(4.10±1.60,6.59±1.38,7.08±2.09 kg)均随母羊营养水平而提高(P＜0.05或P＞0.05)。Ⅰ组母羊泌乳期增重,Ⅱ、Ⅲ组均减重(相应为+0.94±2.05,-0.35±2.74和-1.86±3.89 kg),但组间差异不显著(P＞0.05)。3)3组母羊授乳末体重分别为(46.31±7.61),(46.85±2.58)和(52.93±4.20) kg (P=0.067),断奶后第1次发情分别是在(18.60±12.86),(13.25±6.70)和(10.71±4.07) d,第2情期结束时的空怀率为16.67%,20.00%和14.29%。母羊2次产羔间隔相应为201.8,183.5和187.7 d。     

高山美利奴羊重要经济性状遗传参数估计

本研究旨在估计高山美利奴羊重要经济性状的遗传参数,为优化高山美利奴羊选育方案、建设品种完整结构、进行遗传评估及实施育种值选种提供理论技术支撑。采用甘肃省绵羊繁育技术推广站2003—2018年高山美利奴羊核心群数据资料,基于ASReml运用单性状个体动物模型和多性状个体动物模型估计高山美利奴羊体重、产羔数、产毛量、净毛量、净毛率、羊毛纤维直径、羊毛纤维直径变异系数、毛丛长度等重要经济性状的遗传参数。结果表明:高山美利奴羊产羔数为低等遗传力,其他所有性状均为中高等遗传力;大部分经济性状间呈正遗传相关,体重、产毛量、羊毛纤维直径与净毛率间呈负遗传相关,羊毛纤维直径变异系数与体重、产毛量、纤维直径呈负遗传相关。     

西兰花复种绿肥-当归高效轮作种植技术规程

为进一步挖掘和发挥地区农业资源优势,推进高原夏菜和当归产业健康可持续发展,经过试验示范和生产实践,从范围、规范性引用文件、术语和定义、产地环境、西兰花栽培技术、绿肥复种技术、轮作当归栽培技术等方面制订了西兰花复种绿肥-当归高效轮作种植技术规程,以更好地指导生产。     

Comparison of commonly used primer sets for evaluating arbuscular mycorrhizal fungal communities: Is there a universal solution?

Different primer systems have been developed to characterize arbuscular mycorrhizal fungal (AMF) communities; however, a direct comparison of their specificity, potential to describe diversity and representation of different phylogenetic lineages is lacking. Using seven root samples, we compared four routinely used AMF-specific primer systems for nuclear ribosomal DNA covering i) the partial small subunit (SSU), ii) the partial large subunit (LSU), iii) the partial SSU and internal transcribed spacer (ITS; “Redecker”) and iv) the partial SSU–ITS–partial LSU region (“Krüger”). In addition, a new primer combination v) covering the ITS2 region (ITS2) was included in the comparison. The “Krüger” primers tended to yield the highest AMF diversity and showed a significantly higher Shannon diversity index than the SSU primers. We found a strong bias towards the Glomeraceae in the LSU and SSU primer systems and differences in the composition of AMF communities based on the “Redecker” primer system. Our results confirm the crucial role of the choice of target rRNA marker region for analysing AMF communities. We also provide evidence that nested-PCR based data can be interpreted semi-quantitatively and that the extent of observed AMF community overdominance largely depends on the choice of primer.     

Organic fertilizer effects on pea yield,nutrient uptake,microbial root colonization and soil microbial biomass indices in organic farming systems

In the present field experiment, horse manure and compost derived from shrub and garden cuttings were supplied at nearly equivalent N amounts but different C amounts to field peas (Pisum sativum L.), either as a sole crop or intercropped with oat (Avena sativa L.). The objectives were: (1) to evaluate the beneficial effects of C-rich manure and compost on pea productivity in different cropping systems (2) to investigate whether these effects were reflected by microbial root colonization, microbial biomass and CO₂ production and (3) to study the residual effects of the organic fertilizers on the yield of succeeding crop. Short term application of horse manure and compost greatly stimulated soil microbial biomass C, N, P, fungal ergosterol and CO₂ evolution, but failed to stimulate productivity of the current crops. However, significant positive residual effects of organic fertilizer, especially horse manure were observed on the grain yield of the succeeding winter wheat. Mycorrhizal colonization and ergosterol concentration were significantly higher in pea than in oat roots. Intercropping is an important tool for controlling weeds on pea plots under organic farming conditions, but did not affect microbial root colonization, soil microbial biomass indices or CO₂ evolution from the soil surface. According to the extrapolation of the CO₂ evolution rates into amounts per hectare, approximately 40% of the manure C and 24% of the compost C were mineralized to CO₂ during the 124-day experimental period. There were close relationships between grain N and P concentrations in both crops and microbial biomass C, N and P, suggesting that soil microbial biomass can be used as an indicator of nutrient availability to plants.     

不同耕作措施下陇中黄土高原旱作农田土壤活性有机碳组分及其与酶活性间的关系

通过设置在陇中黄土高原半干旱雨养农业区15年的不同保护性耕作措施长期定位试验,研究了传统耕作(T)、免耕(NT)、免耕结合秸秆覆盖(NTS)、传统耕作结合秸秆还田(TS)4种不同耕作措施下不同土层的土壤总有机碳、土壤活性有机碳、土壤微生物量、碳库管理指数和土壤蔗糖酶、淀粉酶、纤维素酶和过氧化物酶等4种参与碳循环土壤酶,并分析了土壤有机碳及其活性碳组分与土壤酶之间的相关关系。结果表明:0~30 cm土层,NTS处理可显著提高土壤有机碳、土壤活性有机碳、土壤微生物量碳及碳库管理指数,分别较T处理增加了16.3%、28.26%、41.88%、37.04%,NT、TS处理较T处理各指标也均有不同程度提高;在0~30 cm土层,NTS、TS、NT处理与T处理相比,蔗糖酶分别提高了33.84%、21.59%、25.15%,淀粉酶活性分别提高了20.90%、13.43%、12.69%,纤维素酶活性分别提高了39.13%、17.39%、4.34%,过氧化物酶活性分别提高了7.81%、2.08%、3.65%;土壤蔗糖酶、淀粉酶、纤维素酶、过氧化物酶与各形态有机碳及碳库管理指数均表现为显著或极显著正相关关系;蔗糖酶活性增加对有机碳积累作用最显著,有助于土壤总有机碳、活性有机碳、微生物量碳含量提高,土壤纤维素酶对土壤总有机碳和活性有机碳含量的增加有促进作用,过氧化物酶有利于总有机碳的积累。免耕结合秸秆覆盖是适宜该地区农田生态系统健康稳定发展,减少碳库损失的重要途径。     

低温胁迫下冬油菜陇油7号根部代谢组学分析

为了解白菜型冬油菜陇油7号超强抗寒生理机制,采用液相色谱质谱(LC-MS)分析了低温胁迫条件下陇油7号根部代谢组学变化。KEGG富集分析发现,变化显著的代谢通路为:果糖和甘露糖代谢、淀粉和蔗糖代谢、花生四烯酸代谢、苯丙氨酸代谢、甘油磷脂代谢、半乳糖代谢、α-亚麻酸代谢、氨基酸生物合成、精氨酸和脯氨酸代谢以及半胱氨酸和蛋氨酸代谢。糖类、氨基酸、甘油磷酰胆碱、黄酮、6种磷脂(PG、PC、PE、PI、PS和PA)等均得到鉴定,其中糖(除鼠李糖外)、赖氨酸-缬氨酸、脯氨酸-色氨酸和黄酮在低温处理后差异倍数均大于1.2,磷脂中PC在低温胁迫时增加,PC(13∶0/0∶0)亚类差异倍数最高,为5.295,PE和PS在低温胁迫后下降,差异倍数0.528～0.740,PI、PA和PG类的变化因亚类而异。     

Wheat/maize or wheat/soybean strip intercropping: II. Recovery or compensation of maize and soybean after wheat harvesting

While early-maturing crops benefit from intercropping, late-maturing crops usually suffer growth penalties during the intercropping phase. It is possible, however, that recovery or compensation of the late-maturing crops occurs after the harvest of the early-maturing crops. Three field experiments were conducted at Baiyun in 1997 and at Jingtan in 1997 and 1998 to test the hypothesis in wheat/maize and wheat/soybean intercropping. The biomass and nutrient accumulation in intercropped soybean were significantly smaller than in sole soybean before wheat harvest but thereafter increased sharply at Jingtan site in 1997. The rates of dry matter accumulation in the intercropped maize (10.0–20.1 g/m² per day) were significantly lower than those in the sole maize (17.1–34.8 g/m² per day) during the early stage from 7 May to 3 August, while mostly intercropped with wheat. After 3 August, however, the rates of intercropped maize, increasing to 58.9–69.9 g/m² per day, was significantly greater than in sole maize (22.7–51.8 g/m² per day) at Baiyun site in 1997 and nutrient acquisition showed the same trends as growth. At Jingtan site in 1998, the disadvantage of the border row of intercropped maize resulted from interspecific competition diminished after wheat harvest and disappeared at maize maturity. It was concluded that there was indeed recovery of growth after wheat harvesting in wheat/maize and wheat/soybean intercropping. However, the recovery was limited under N₀P₀ treatment. The interspecific competition, facilitation and recovery are together contributed to yield advantage of intercropping.     

不同秸秆还田处理对旱地冬小麦土壤水分的影响

为了更全面地了解秸秆还田对土壤水分的影响,通过田间试验,分时期分土层研究了小麦和玉米两种秸秆在不同处理下还田对西北雨养农区冬小麦土壤水分的影响。结果表明:秸秆还田各处理土壤含水量的差异在时期上表现为前期大于后期,以越冬期的土壤墒情差异最大;在土层上表现为下层大于下层,以120—150 cm土层处理间差异最大。总体表现为:土壤含水量的差异随着生育时期的推进和土层加深而减小。同时,除小麦秸秆还田后不覆膜不镇压（T6）外其余秸秆还田处理的小麦产量和土壤水分利用效率均高于CK。其中,玉米秸秆还田后小麦产量和土壤水分利用效率均高于小麦秸秆还田;秸秆还田不覆膜,镇压（T2,T5）高于不镇压（T3,T6）。全生育期200 cm土体墒情秸秆还田好于露地（CK）,秸秆还田覆膜（T1,T4）好于不覆膜（T2,T3,T5,T6）。无论是增产还是保墒,秸秆还田和地膜覆盖组合模式是最好的。     

甘肃省中药材种业现状及发展对策

甘肃省是中药材生产大省,中药材产业是甘肃省“六大支柱产业”之一,中药材种业是中药材产业化的基础,建设特色中药材种业强省对提高甘肃省药材品质、保障药源安全、促进乡村振兴具有重要意义。基于对甘肃省中药材种业发展现状的调研,系统分析了中药材种业存在的问题,从加强种质资源的收集、整理、保存和利用研究;重视新品种选育,加速品种选育进程;加强种子种苗繁育基地建设;鼓励推进制种园区建设;加大金融支持强度;建立种子种苗生产经营许可制度等方面提出了对策。