Identification and validation of stable and novel quantitative trait loci for pod shattering in soybean [Glycinemax (L.) Merr.]

Pod shattering is an important domesticated trait which can cause great economic loss of crop yield in cultivated soybean. In this study, we utilized two recombinant inbred line populations (RILs, CY, Huachun 2×Wayao; GB, Guizao 1× B13) to identify quantitative trait loci (QTLs) associated with pod shattering in soybean across multiple environments. A total of 14 QTLs for pod shattering were identified in the two RIL populations, which had LOD scores ranging from 2.64 to 44.33 with phenotypic variance explanation (PVE) ranging from 1.33 to 50.85%. One QTL qPS16-1, located on chromosome 16, included a well-known functional gene Poddehiscence1 (Pdh1) that was reported previously. Ten new putative QTLs were validated in two RIL populations, and their LOD scores were between 2.55 and 4.24, explaining 1.33 to 2.60% of the phenotypic variation. Of which four novel QTLs (qPS01-1, qPS03-2, qPS05-1, and qPS07-1) could be detected in two environments where nine genes had specific changes in gene expression. Although the nine genes may have significant effects on pod shattering of soybean, their detailed functions still need to be further explored in the future. The results of this study will facilitate a better understanding of the genetic basis of the pod shattering-resistant trait and benefit soybean molecular breeding for improving pod shattering resistance.     

响应面法优化红树莓色素的纳滤浓缩条件

为了确定纳滤法浓缩红树莓色素的最佳工艺条件,以红树莓色素溶液为原料,选取截留分子量为300u的纳滤膜浓缩纯化红树莓色素。以红树莓色素浓缩度衡量纳滤效果。通过单因素试验确定了温度、压力、进料质量浓度、pH对纳滤效果的影响。在此基础上,以色素浓缩度为响应值,利用响应面优化法,通过部分因子试验和中心组合试验设计,对纳滤法浓缩红树莓色素的最佳工艺条件进行了研究。得到最优条件为,纳滤温度为30℃,压力为0．6MPa,进料花色苷质量浓度为10．94mg／L,pH为3．12,此时色素截留率为98．26％。动态试验显示,红树莓色素纳滤法浓缩后浓缩度可达3．996。因此,纳滤法浓缩纯化为红树莓色素提取后加工提供了便捷稳定可行的方法。     

黑斑侧褶蛙5类抗菌肽基因的克隆及其成熟肽理化性质的预测

抗菌肽是蛙类非特异性免疫的重要组成部分,蛙类对环境变化比较敏感,但仍能分布于广泛的地理区域,抗菌肽的多样性和组成是揭示其适应机制的基础。本研究通过RT-PCR技术,从1只黑斑侧褶蛙的皮肤组织中克隆了9条不同的cDNA序列,分属5个家族:Esculentin-1、Esculentin-2、Temporin、Nigrocin-1和Nigrocin-2。其中Esculentin-1、Esculentin-2、Temporin和Nigrocin-1为阳离子抗菌肽,等电点(PI)8.72～9.63,分子量(Mw)1495.87～4862.9,预测的二级结构都具有α-螺旋结构。Nigrocin-2为新发现的一类酸性抗菌肽,等电点PI为4.0,Mw为1798.06,带1个负电荷,预测二级结构不具有α-螺旋结构,呈无规则卷曲。这9条抗菌肽cDNA来自50个阳性克隆,显示出黑斑侧褶蛙抗菌肽具多样性,特殊抗菌肽的发现也预示着黑斑侧褶蛙适应复杂多变环境、分布广泛的生理潜能,但具体功能还需进一步研究。     

野生小豆和栽培小豆microRNA全基因组鉴定与比较分析

microRNA(miRNA)是一种非编码的小RNA分子, 对真核生物基因表达起着非常重要的调控作用,miRNA系统鉴定对于研究其功能及作用机制具有重要意义。本研究分别以栽培小豆京农6号(JN6)和野生小豆CWA108为试验材料,进行了深度miRNA测序。系统鉴定和注释这2个物种的miRNA,并分析了其miRNA种类的异同、表达量的差异和靶基因在功能富集上的差别。鉴定出了JN6和CWA108共有和特有的miRNA,明确了它们之间差异表达的miRNA,以及这些特有和差异miRNA的靶基因在功能富集上的差异,发现可能和抗病与抗逆途径相关。     

水稻低温胁迫不同时间的代谢物谱图分析

苗期低温严重影响水稻幼苗生长, 分析低温胁迫下幼苗体内代谢物变化特征有助于解析水稻应对胁迫的生理机制。采用气质谱联用仪(GC-MS)技术系统分析水稻品种IR64遭遇不同时间段低温后代谢物图谱的变化特征。结果表明, 草酸、戊糖酸-1,4-内酯、海藻糖及水杨酸参与了水稻低温胁迫早期应激性反应; 在低温胁迫过程中, 水稻植株主要通过苯丙氨酸、脯氨酸、谷氨酸、丝氨酸、苏氨酸、天门冬氨酸、缬氨酸、木糖醇、尿囊素和鼠李糖等含量的提高维持细胞渗透平衡。代谢物动态分析发现参与低温胁迫反应及胁迫恢复后进程的主要代谢物不同。研究结果为全面系统剖析水稻耐冷胁迫的分子生理机制打下了基础。     

念珠藻多糖的研究现状与应用展望

念珠藻多糖是念珠藻群体的主要支撑物质,也是念珠藻的主要生物活性成分之一。念珠藻多糖在增强机体免疫、抗肿瘤、抗病毒等方面有显著活性,同时念珠藻胞外多糖对念珠藻本身在抗逆境等方面具有良好的保护作用。综述了念珠藻多糖的提取分离、结构与生物活性三方面对念珠藻多糖的研究进展,并在此基础上展望了对念珠藻多糖在医药保健、日用化工和环境保护等领域的开发潜力和应用前景。     

Consumers’ beliefs about whole and refined grain products in the UK,Italy and Finland

The objective of this study was to increase our understanding of consumers’ product related expectations that may influence their willingness to use whole grain (WG) foods. Consumers’ beliefs about WG and refined grain (RG) product categories were measured, compared and consumers were segmented based on these beliefs. Data were collected with self-completion questionnaires in the UK (N=552), Italy (N=504), and Finland (N=513).On average, consumers in Finland, Italy and the UK were aware that WG products are healthier than RG products as the WG product category was rated as more nutritionally balanced, healthier, more natural, more filling, releasing energy more slowly and slightly more digestible than the RG product category. However, certain consumer segments did not perceive much difference between whole and RG products in their health-related characteristics suggesting a lack of motivation for increasing WG consumption. This sets a challenge for promoting WG products especially in Italy and the UK, where the respondents were less likely to differentiate between the healthiness of WG and RG products than the Finnish respondents. Differences between the consumer segments and ways of promoting WG consumption are discussed.     

Season-Long vs Intensive-Early Stocking with Growing Cattle Grazing Bermudagrass Pasture

Our objective was to compare the performance of weaned steer calves managed with intensive-early stocking (IES; 12.4 steers per ha for 70 d) or season-long stocking (SLS; 6.2 steers per ha for 140 d) with and without supplementation (2 × 2 factorial). Beginning on May 15, 90 steers (BW = 217 ± 0.8 kg) were randomly assigned to one of 12 common bermudagrass (Cynodon dactylon [L.] Pers.) pastures (0.81 ha each) fertilized with 168 kg of nitrogen/ha. One of the following four treatments was randomly applied to three pastures: i) SLS plus no supplement, ii) SLS plus 0.45 kg/steer of ground corn daily, iii) IES plus no supplement, and iv) IES plus 0.45 kg/steer of ground corn daily. Steers on IES were lighter (P=0.01) than SLS steers on d 70. By d 140, SLS steers supplemented with corn were 33 kg heavier (P=0.02) than nonsupplemented steers. When using SLS, corn increased the BW gain 0.5 kg/kg of corn fed; however, when IES was used, there was no benefit from corn supplementation. Total BW gain/ha did not differ (P>0.17) among treatments, but SLS with corn supplementation could have the potential to produce more BW gain/ha compared to the other treatments. Grazing systems did not affect feedlot ADG (P>0.53), but IES (175 d on feed) steers did have a higher (P<0.01) feedlot total BW gain than the SLS steers (154 d on feed). Using IES positively affected (P<0.08) dressing percentage and longissimus area compared to SLS; however, these differences in carcass characteristics were probably the result of the longer feeding period.     

Characterization of a novel male sterile mutant of Tagetes patula induced by heat shock

Tagetes patula L. is an annual plant belonging to the Asteraceae family. Currently, commercial F₁ cultivars are produced through the use of artificial emasculation which is a very laborious procedure, particularly in view of the composite capitulum structure. To date, no male sterile line is available in this species, but the isolation of such material would provide a valuable tool for the establishment of an efficient cross-pollination system for the production of F₁ hybrids. In this study, we report the characterization of a novel pollen abortion mutant of Tagetes patula which was isolated from 1,796 heat shock induced cutting seedlings. Histological and cytological observation demonstrated that the abnormal development of the microspores during the binucleate pollen stage led to pollen abortion, and this was correlated to premature tapetum degeneration. Cross hybridization experiments indicated that a recessive nuclear gene was responsible for the trait. This novel male sterile mutant of Tagetes patula appears to be an applicable material for improving the breeding efficiency of the species and may be used to significantly improve ornamental traits in F₁ generations.