玉米杂交组合产量与农艺性状的灰色关联度分析

以灰色系统理论为依据,采用灰色关联度分析法,对15个玉米杂交组合的子粒产量与14个农艺性状的相关性状进行分析。结果表明,玉米杂交组合的产量是由多种因素控制的,农艺性状中影响产量的因素顺序为:生育期>出籽率>行粒数>穗长>穗粗>千粒重>株高>穗行数>轴粗>穗位高>秃尖长>双穗率>倒伏率>空秆率。生育期、出籽率、行粒数、穗长、穗粗、千粒重等因素与产量的关系密切,对产量的构成影响较大。     

茶树EST SSRs特点及应用

利用NCBI公共数据库下载获得的3 306条茶树EST,去除其中低质量和冗余的序列,得到全长为635.46 kb的1 335条无冗余EST,在这些序列中共发现216个SSR,分布于185个EST中,出现的频率为16.18%,平均每2.94 kb的表达序列中有1个SSR。茶树的EST-SSR类型丰富,其中二核苷酸重复出现的频率最高,占主导地位。利用Primer 5.0软件从185条含有SSR的EST中设计引物100对,从中随机选取60对引物检测EST-SSR在云南茶树资源中的多态性。结果表明,有30对引物在供试的63份茶树资源中得到有效扩增,并具有多态性;共检测到等位基因数71个,每对引物检测出的等位基因数2~8个,平均4.9个;多态信息量(PIC)变幅为0~0.731,平均为0.499;观察杂合度变幅为0~0.970,平均0.392。EST-SSR标记分析表明云南茶树资源具有较高的遗传多样性。     

藏香猪屠宰特性及肉品质的分析

按照随机抽样的原则,选择饲养条件基本一致的成年去势公猪9头,对其屠宰性能和肉品质进行测定。结果表明,藏香猪的平均屠宰率为75.75%,瘦肉率为46.88%,含脂率为29.48%。体组分分析表明,头、蹄、内脏占活体质量的百分比均比内地饲养的瘦肉型猪的体组分高。相关性分析表明：屠宰率和大肠质量之间相关性显著（R=0.995,P=0.05）,藏香猪肌肉脂肪酸组成主要是C16 和C18 脂肪酸,以棕榈酸（C16∶0）、硬脂酸（C18∶0）、油酸（C18∶1）和亚油酸（C18∶2）为主,这4种脂肪酸的相对含量分别为23.22%、10.76%、46.39%、13.39%。粗蛋白平均含量为19.45%,每100 g背最长肌中氨基酸总量、鲜味氨基酸量和必需氨基酸量分别为17.00、7.401、6.50 g,鲜味氨基酸和必需氨基酸占氨基酸总量的比例分别为43.56％和38.22％。矿物质含量丰富,尤其是Fe和Ca（Fe含量为35.15 mg/kg,Ca为36.65 mg/kg）含量较高。     

脂联素基因c.249 C>T突变对京海黄鸡部分主要经济性状的影响

以京海黄鸡为试验材料,采用PCR-SSCP技术,探讨脂联素基因第一外显子和部分第一内含子碱基突变对屠宰和母鸡产蛋性状的遗传效应。结果表明,脂联素基因c.249位C>T突变的3种基因型(AA、AB和BB)对京海黄鸡的活体质量、半净膛率、胸肌质量、腿肌质量、胸肌率和腿肌率差异均不显著(P>0.05)。BB型个体的300日龄产蛋数和66周龄产蛋数显著高于AB型个体(P<0.05)。BB型个体的腹脂质量和腹脂率显著高于AB和AA型个体(P<0.05)。Adipo基因座对京海黄鸡开产日龄,300日龄产蛋数,300日龄蛋质量和66周龄产蛋数的主效应指数(MEI)均小于1.21,而其对公母鸡的腹脂质量主效应指数(MEI)分别为8.68和7.40。说明该基因可能是调控脂肪沉积的主效基因或与主效基因连锁。     

呋喃它酮代谢物AMOZ单克隆抗体的制备与免疫学特性鉴定

用碳二亚胺(DCC)一步法将对醛基苯甲酸衍生物CPAMOZ偶联于牛血清白蛋白、卵清蛋白上,合成免疫原CNPAMOZ-BSA、包被原CNPAMOZ-OVA。用紫外线扫描、SDS-PAGE进行人工抗原合成的鉴定;免疫Balb/c小鼠,用杂交瘤技术建立分泌NPAMOZ mAb的细胞株;对NPAMOZ mAb的效价、敏感性和特异性进行鉴定。结果表明,CPAMOZ-BSA人工抗原分子结合比为15∶1;筛选出分泌NPAMOZ mAb的敏感特异的杂交瘤细胞1株2D11-B4,间接ELISA测定细胞培养上清,效价达到1∶(6.4×102),腹水效价为1∶(1.2×106),对NPAMOZ IC50为7.58μg/L,与其他抗生素交叉反应率低。本试验获得了抗NPAMOZ高价、敏感、特异的mAb,可用于呋喃它酮代谢物AMOZ的残留检测。     

叶面喷施天然海盐和尿素对苦瓜品质的影

在苦瓜苗期喷施天然海盐和尿素,成熟期检测苦瓜的比叶面积、矿质元素、叶绿素、氨基酸、维生素Ｃ的含量和抗氧化活性等生理指标,以探明叶面喷施天然海盐和尿素对苦瓜食品价值的影响。结果表明：叶面喷施尿素,降低了苦瓜的光合效率,提高了矿质元素 Ｍｇ,Ｓｉ,Ｐ,Ｋ和各种氨基酸的含量,特别是苦瓜体内的叶绿素 ａ和 ｂ的含量。喷施海盐显著地提高了苦瓜叶片的光合效率,促进了对 Ｍｇ,Ｓｉ,Ｐ,Ｓ,Ｋ的吸收,增加了叶绿素 ａ,ｂ的含量 （增量低于尿素处理）,增加了天冬氨酸、缬氨酸、亮氨酸、酪氨酸、苯丙氨酸、赖氨酸、组氨酸和精氨酸的含量,提高了维生素 Ｃ的含量和抗氧化活性。尿素和海盐组合处理显著提高了苦瓜对 Ｋ的吸收,提高了天冬氨酸的含量,但其它氨基酸的含量并没有尿素处理的高。综上所述,叶面喷施天然海盐和尿素改善了苦瓜的某些品质。由于海盐和尿素单独使用的局限性,因此合理分配海盐和尿素的比例或适当补充某些矿质元素进行叶片处理,可能更有利于苦瓜的品质。     

麻城黑山羊及杂交后代的胴体品质与肉质特性

分析麻城黑山羊及杂交后代胴体品质与肉质特性,探讨麻城黑山羊的改良和新品系选育。选用麻城黑山羊(Ⅰ,对照组)、波尔山羊×麻城黑山羊(Ⅱ)、麻城黑山羊×波麻F1(Ⅲ)、波麻F1×波麻F1(Ⅳ)和波尔山羊×波麻F1(Ⅴ)5组,以放牧加补饲的方式育肥,试验期90d,于试验始日及第90天称量,试验结束时于每个组选取12只屠宰并分析胴体品质和肉质性状。结果表明,杂交后代的肥育性能较麻城黑山羊组均有所提高,其中Ⅱ、Ⅲ、Ⅴ组的日增量极显著高于麻城黑山羊(P<0.01);杂交后代的胴体性状较麻城黑山羊有较大提高,其中Ⅱ、Ⅴ组的屠宰率和净肉率分别显著、极显著高于麻城黑山羊(P<0.05,P<0.01),Ⅱ、Ⅳ组的肉骨比显著高于麻城黑山羊(P<0.05),Ⅱ、Ⅴ组的眼肌面积极显著高于麻城黑山羊(P<0.01);各组间主要肉质性状除麻城黑山羊宰后24h的pH显著高于Ⅱ、Ⅳ组(P<0.05)外,其余差异均不显著(P>0.05);Ⅲ组的Fe含量显著高于麻城黑山羊(P<0.05),杂交后代肌肉的氨基酸组分完全,且氨基酸总量和鲜味氨基酸含量均高于麻城黑山羊。结果显示,Ⅱ组是肉羊生产理想的杂交组合,Ⅴ组可用于进一步培育麻城黑山羊新品系的研究。     

Genetic gains in grain yield, net photosynthesis and stomatal conductance achieved in Henan Province of China between 1981 and 2008

Knowledge of the changes in agronomic and photosynthetic traits associated with genetic gains in grain yield potential is essential for an improved understanding of yield-limiting factors and for determining future breeding strategies. The objectives of this study were to identify agronomic and photosynthetic traits associated with genetic gains in grain yield of facultative wheat (Triticum aestivum L.) between 1981 and 2008 in Henan Province, the most important wheat producing area in China. During the 2006-2007 and 2007-2008 crop seasons, a yield potential trial comprising 18 leading and new cultivars released between 1981 and 2008 was conducted at two locations, using a completely randomised block design of three replicates. Results showed that average annual genetic gain in grain yield was 0.60% or 51.30 kg ha⁻¹ yr⁻¹, and the significant genetic improvement in grain yield was directly attributed to increased thousand grain weight which also contributed to the significant increase in harvest index. The genetic gains in rates of net photosynthesis at 10, 20 and 30 days after anthesis were 1.10% (R² = 0.46, P < 0.01), 0.68% (R² = 0.31, P < 0.05) and 6.77% (R² = 0.34, P < 0.05), respectively. The rates of net photosynthesis at 10 (r = 0.58, P < 0.05), 20 (r = 0.59, P < 0.05) and 30 (r = 0.65, P < 0.01) days after anthesis were closely and positively correlated with grain yield. A slight decrease in leaf temperature and an increase in stomatal conductance after anthesis were also observed. Grain yield was closely and positively associated with stomatal conductance (r = 0.69, P < 0.01) and transpiration rate (r = 0.63, P < 0.01) at 30 days after anthesis. Therefore, improvement of those traits was the likely basis of increasing grain yield in Henan Province between 1981 and 2008. The genetic improvement in yield was primarily attributed to the utilization of two elite parents Yumai 2 and Zhou 8425B. The future challenge of wheat breeding in this region is to maintain the genetic gain in grain yield and to improve grain quality, without increasing inputs for the wheat-maize double cropping system.     

Yield benefits of triticale traits for wheat under current and future climates

Triticale often out-yields wheat in both favourable and unfavourable growing conditions. Observed traits suggested for the higher yields in triticale include greater early vigour, a longer spike formation phase with same duration to flowering, reduced tillering, increased remobilization of carbohydrates to the grain, early vigorous root growth and higher transpiration use efficiency. To quantify the impact of these traits systematically across seasons and contrasting rainfall regions and soil types, these triticale traits were introduced into a wheat model (APSIM-Nwheat). The impact of each individual trait and their full combination was analysed in a simulation experiment for three Mediterranean growing environments, two contrasting soil types and long-term historical weather data. The simulated impact of these traits was compared with measured impacts from a range of field experiments across several environments. Simulated responses of various crop characteristics including yield, were in general similar to responses observed in wheat-triticale comparison field experiments across a large range of growing conditions. The simulation analysis indicated that the yield response to the incorporation of the triticale traits into wheat was positive, in both low and high yielding growing conditions, similar to measured differences, but the simulated benefit was on average lower than the range observed in data of triticale and wheat. This suggests that other traits might also be involved in higher-yielding triticale, or the magnitude of some of the traits may be underestimated in field experiments due to ‘trait by environment’ interactions. The simulation results suggest the highest yield benefit can be achieved from increasing transpiration use efficiency in wheat, but early vigour, remobilization of stem carbohydrates and early root growth also contribute positively to a yield increase in the different growing environments. The yield benefits from the triticale traits increased in the future climate change scenario in particular on soils with high water-holding capacity from contributions of increased early vigour, remobilization of stem carbohydrates and transpiration use efficiency, and remained stable on the lighter soils.     

Natural variation and morpho-physiological traits associated with water-soluble carbohydrate concentration in wheat under different nitrogen levels

Stem water-soluble carbohydrates (WSCs) are important plant traits influencing grain yields in wheat. However, the traits regulating WSCs storage, particularly under different nitrogen (N) levels are poorly addressed. This study investigated 35 morpho-physiological traits associated with the variation in WSC concentration (WSCc) in the main stem of eight wheat genotypes including two primitive genotypes under three N levels (0, 100, and 200 kg N ha⁻¹). 28 traits were significantly, positively or negatively, correlated with the WSCc in all N levels, and 22 of them were consistent across N levels. Majority of the traits were positively correlated with WSCc suggesting that multiple traits regulate WSCc in wheat plants. However, few traits such as root:shoot ratio (RS_R), stem nitrogen (S_N), leaf nitrogen (L_N), nitrogen per unit leaf area (N_LA), total vegetative mass (V_MASS), cellulose (C_L), and hemicellulose (H_C), were negatively correlated with WSCc. This suggests that plant N concentration was an important selective force driving WSCc in wheat. Indeed, a percent increase in leaf N concentration resulted in 28% lower WSCc. Direct selection estimated that higher V_MASS, flag-leaf width (FL_W), but lower RS_R was adaptive and resulted in higher WSCc in low N level. In contrast, lower V_MASS and FL_W were adaptive and resulted in higher WSCc in high N level. Higher cellulose and hemicellulose were associated with lower WSCc suggesting that a reduced carbon flux to stem structural compounds may improve WSCc in wheat plants. Together, these results demonstrate that a specific suit of trait changes that evolve under N-specific selection increase main stem WSCc but the adaptive value of these changes varies among traits and N levels.