生物菌剂对玉米秸秆堆沤过程水热状况及酶活性的影响

为解决内蒙古西辽河平原地区还田玉米秸秆腐解困难及腐解周期长等问题,于2020年采用田间秸秆动态堆沤快速腐解试验,分别设置秸秆腐熟剂+秸秆（SRT）、新鲜牛粪+秸秆（SRN）、秸秆腐熟剂+新鲜牛粪+秸秆（SRW）、单一秸秆（CK）4种处理,研究不同外源生物菌剂对堆沤玉米秸秆温度、水分、纤维素酶、脲酶和木质素过氧化氢酶的影响。结果表明,添加秸秆腐熟剂和新鲜牛粪均可提高秸秆腐解速率,并缩短腐解时间。与单一秸秆堆沤相比,添加新鲜牛粪和秸秆腐熟剂均能显著提高堆体秸秆温度和含水率;SRW、SRT和SRN处理纤维素酶活性较CK分别提高15.64%、4.87%和7.96%,脲酶活性分别提高10.29%、3.43%和6.86%,木质素过氧化氢酶活性分别提高71.43%、48.05%和53.25%。因此,添加秸秆腐熟剂和新鲜牛粪可改善堆沤秸秆水热条件和提高秸秆水解酶活性,进而加快秸秆堆沤腐解进程,两者耦合使用效果更佳,可作为一种高效秸秆堆沤方式在内蒙古西辽河平原地区推广应用。     

基于温度植被干旱指数的曲靖市干旱监测研究

本研究利用MODIS归一化植被指数(NDVI)和地表温度(Ts)产品数据,构建Ts-NDVI特征空间,计算温度植被干旱指数(TVDI),分析评价云南曲靖市2010—2012年的干旱时空分布状况。结果表明,2010年曲靖市遭遇了非常严重的干旱灾害,受灾面积高达研究区总面积的80%以上,基于TVDI指数的旱情动态监测方法适合云南省曲靖干旱监测。本研究建立的温度植被干旱指数模型提高了干旱监测的实用性,在曲靖市干旱监测上具有很好的适应性,可以广泛应用到该地区干旱监测研究中,为曲靖的农业防灾减灾能力和可持续发展提供科学保障。     

山核桃仁碱法脱涩工艺研究

为探索一种利用NaHCO₃对山核桃仁脱涩的碱法脱涩工艺,基于综合了脱涩率与感官评分的响应值,通过单因素试验和响应面试验优化其工艺参数,并对比碱法脱涩与传统的沸水脱涩对山核桃仁游离酚、结合酚含量,以及过氧化值、碘值、酸价等指标的影响。结果显示:优化后的碱法脱涩工艺参数为脱涩温度65 ℃,脱涩时间100 min,NaHCO₃质量分数5%,固液比(g·mL^-1)1∶15。在此条件下,山核桃仁的脱涩率为92.04%,感官评分为9.2分,响应值为75.47。与沸水脱涩相比,碱法脱涩既能去除苦涩味,又能更大限度地保留山核桃仁中的结合酚,减少油脂、脂肪酸和不饱和脂肪酸的氧化,从而更好地保持山核桃仁的品质。     

Dietary quercetin improved the growth,antioxidation, and flesh quality of grass carp (Ctenopharyngodon idella)

To investigate the effects of dietary quercetin on growth, antioxidation, and flesh quality of grass carp, Ctenopharyngodon idella, six diets were prepared with quercetin inclusion rates of 0 (control diet), 0.1, 0.2, 0.4, 0.6, and 0.8 g/kg. Grass carp with a body weight of 13.3 ± 0.1 g were fed with one of the six diets for 60 days. The weight gain (WG) showed a quadratic relationship with dietary quercetin levels; the supplementation of 0.4 g/kg quercetin significantly improved WG (+4.73%) and decreased feed conversion ratio (?0.06) (p < .05) when compared to those of the control group. The intestinal fat ratio was reduced by the addition of 0.2 or 0.4 g/kg of quercetin (p < .05), and serum activities of alkaline phosphatase and superoxide dismutase were increased by the addition of 0.4 and 0.6 g/kg of quercetin (p < .05). The inclusion of 0.2–0.6 g/kg of quercetin increased the contents of delicious amino acids and decreased the cooking loss of flesh (p < .05). Flesh collagen content was increased by the addition of 0.4–0.8 g/kg of quercetin (p < .05). In conclusion, dietary quercetin could improve the growth and enhance the antioxidation and flesh quality of grass carp, with the recommended supplemental level of quercetin was 0.37 g/kg.     

蒺藜苜蓿转录因子MtMYB的克隆、表达分析及拟南芥转化

MYB转录因子家族基因具有保守的DNA结合域,是植物最大的转录因子家族之一,广泛参与植物的代谢调控,在植物生长发育和胁迫响应等方面发挥重要作用。为改良品种性状和提高生产实践能力,本研究采用RT-PCR法克隆蒺藜苜蓿MYB转录因子基因MtMYB,其编码区长255 bp,编码84个氨基酸。生物信息学分析表明,该基因编码蛋白与其他物种MYB蛋白具有很高的同源性,其中与红三叶同源性最高。荧光定量结果表明,MtMYB基因在蒺藜苜蓿叶片中的表达量最高。MtMYB基因在外源IAA、6-BA的诱导下,总体都呈现先上升后下降的趋势。同时本研究成功构建35S::MtMYB的植物表达载体,并通过转基因技术将其转化至拟南芥中,PCR检测表明,MtMYB已成功整合至转基因拟南芥基因组中。RT-PCR检测表明,MtMYB能够在转基因拟南芥中正常转录。本研究为进一步探明MtMYB基因的功能提供了数据参考和实验材料。     

海南岛白唇竹叶青蛇扩散的初步研究

据《中国动物志》记载,海南岛的竹叶青蛇为两个物种,即白唇竹叶青蛇和福建竹叶青蛇。为研究白唇竹叶青蛇在海南岛上的扩散路线,作者采集了海南岛不同方位的标本共12号,PCR扩增其12S、16S、Cyt b、ND_4四个线粒体基因序列,共约1 446 bp,并从GenBank下载了10个个体的Cyt b和ND_4基因序列;通过绘制单倍型的统计简约网络图,进行原始单倍型分析,再绘制扩散路线图。结果显示,采自海南岛西部的单倍型较多,故初步得出结论,白唇竹叶青蛇在岛上很可能自西向东扩散。     

海南琼中县全力打造"琼中绿橙"品牌

海南省琼中黎族苗族自治县位于海南岛中部,五指山脚下,全县有土地总面积2693平方公里,人口20.36万人,是典型的山区县和少数民族集居县,属热带和亚热带气候,年均气温22.8度,年均日照1743.1小时,年均降水量2444mm,冬无严寒、夏无酷暑,四季如春,生态环境优美,生态环境综合指数经国家环保部门评定位居全国第四位.     

Quantitative trait loci mapping of forage agronomic traits in six mapping populations derived from European elite maize germplasm

Four agronomic traits were analysed including dry matter concentration (DMC) and dry matter yield (DMY) for stover, plant height (PHT) and days from planting to silking (DPS). We mapped quantitative trait loci (QTL) in three populations with doubled haploid lines (DHL), one RIL population and two testcross (TC) populations derived from crosses between two of the four populations mentioned above to elite tester lines, based on field phenotyping at multiple locations and years for each; 146–168 SSRs were used for genotyping of the four mapping populations. Significant high phenotypic and genotypic correlations were found for all traits at two locations, while DMC was negatively correlated with the other traits. A total of 42, 41, 54, and 45 QTL were identified for DMC, DMY, PHT, and DPS, respectively, with 9, 7, 12, and 7 major QTL for each trait. Most detected QTL displayed significant interactions with environment. Major QTL detected in more than two populations will contribute to marker‐assisted breeding and also to fine mapping candidate genes associated with maize agronomic traits.     

播期、密度及施肥对寒地油用型紫苏产量的影响

以“SU-5”为研究对象,通过二次回归通用旋转组合设计,研究播期、密度、复合肥施用量3种因素对寒地油用型紫苏种子产量的影响。结果表明：3个参试因子对寒地紫苏产量的影响是密度>复合肥施用量>播期,寒地紫苏种子产量的二次回归通用旋转组合方程为Y=2214.74973+111.16360X₁+225.68963X₂+190.45268X₃-210.46885X₁ ²-212.67802X₂ ²-126.52061X₃ ²-196.87500X₂X₃。通过方差分析得出,寒地紫苏种子产量大于1 839.38kg/hm ²的理论上组合方案的播期为5月4日,最佳密度为5.0万株/hm ²,最佳复合肥施用量为507.7kg/hm ²。     

Comparative study on the utilization of crystalline methionine and methionine hydroxy analogue calcium by Pacific white shrimp (Litopenaeus vannamei Boone)

The objective of this study was to compare the supplemental effects of crystalline DL‐methionine (DL‐Met) and methionine hydroxy analogue calcium (MHA‐Ca) on growth performance of Pacific white shrimp. Eight isoproteinic (355.3 ± 2.0 g/kg diet) and isolipidic (70.0 ± 2.2 g/kg diet) diets were prepared as positive diet (20% fish meal), negative diet (15% fish meal) and DL‐Met, MHA‐Ca‐supplemented diets with the supplementation of 0.03%, 0.06%, 0.09% DL‐Met and 0.04%, 0.07%, 0.1% MHA‐Ca in negative diet respectively. Pacific white shrimp (0.92 ± 0.03 g) were fed one of the eight diets for 49 days. The results showed that dietary DL‐Met did not affect weight gain (WG) and feed conversion ratio (FCR) (p > 0.05), but the supplementation of 0.1% MHA‐Ca significantly increased WG, protein and lipid retention, and reduced FCR (p < 0.05) when compared to the negative group, and reached the similar levels as the positive control. The total free amino acids (TFAA) in haemolymph of MHA‐Ca groups and PC, NC group peaked at the 3rd hr after feeding, but the peaking time of DL‐Met groups was advanced to the 2nd hr. Activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in haemolymph of all MHA‐Ca groups peaked at the 2nd hr, but DL‐Met groups peaked at the 1st hr after feeding. The above results indicated that the supplementation of 0.1% MHA‐Ca in a low fish meal diet could improve the growth performance and feed utilization of Pacific white shrimp, but dietary DL‐Met did not significantly affect the growth.