Development of SCAR and CAPS Markers for a Partially Dominant Yellow Seed Coat Gene in Brassica Napus L

Summary We have previously identified 2 RAPD and 8 AFLP markers that were associated with yellow seed coat gene in a stable and pure yellow-seeded DH line No. 2127-17, however, they were not suitable in large-scale MAS. In this paper, it reported our efforts in developing rapid and reliable SCAR and CAPS markers from the RAPD and AFLP markers. Based on the sequence information in the regions of the most closely linked 4 AFLP and 2 RAPD markers, one SCAR (SCS1130) and one CAPS (SCA1) maker were successfully developed. Linkage analysis on a 127 DH lines population derived from the cross Hui5148-2 × No. 2127-17 revealed that they were tightly flanked (3.2 cM, 3.8 cM respectively). The resulting SCS1130 and SCA1 were further evaluated in backcross breeding families and demonstrated more accurate and valuable in MAS breeding. The development of these new markers would facilitate and accelerate the yellow seed coat breeding in Brassica napus.     

Identification of novel QTL for resistance to crown rot in the doubled haploid wheat population 'W21MMT70' × 'Mendos'

Crown rot (causal agent Fusarium pseudograminearum) is a fungal disease of major significance to wheat cultivation in Australia. A doubled haploid wheat population was produced from a cross between line ‘W21MMT70’, which displays partial seedling and adult plant (field) resistance to crown rot, and ‘Mendos’, which is moderately susceptible in seedling tests but partially resistant in field trials. Bulked segregant analysis (BSA) based on seedling trial data did not reveal markers for crown rot resistance. A framework map was produced consisting of 128 microsatellite markers, four phenotypic markers, and one sequence tagged site marker. To this map 331 previously screened AFLP markers were then added. Three quantitative trait loci (QTL) were identified with composite interval mapping across all of the three seedling trials conducted. These QTL are located on chromosomes 2B, 2D and 5D. The 2D and 5D QTL are inherited from the line ‘W21MMT70’, whereas the 2B QTL is inherited from ‘Mendos’. These loci are different from those associated with crown rot resistance in other wheat populations that have been examined, and may represent an opportunity for pyramiding QTL to provide more durable resistance to crown rot.     

Prediction of heterosis using QTLs for yield traits in rapeseed (Brassica napus L.)

Three double low (erucic acid and glucosinolates) self-incompatible lines and 22 varieties from different origins were selected to produce 66 hybrids according to a NC II mating design. Field experiments for identification of hybrid performance and heterosis were conducted in two successive rapeseed growing seasons in Wuhan, China. After heterosis identifications, SI-1300 and Eagle were chosen to construct an F₂ segregating population. One hundred and eighty four F_2:3 lines were planted at Wuhan and Jingmen to test yield traits. F₂ plants and the 25 parents were analyzed using simultaneously AFLP (amplified fragment length polymorphism) and SSR (simple sequence repeat) markers. A total of 270 and 718 polymorphic loci were detected in the F₂ population and among the 25 parental lines, respectively. Of the 718 polymorphic loci, 178 were significantly correlated to yield traits. With the use of one-way ANOVA, 84 common QTLs were detected for 12 traits at two trial locations. Although the genetic distances based on general/specific heterozygosities and single-locus QTLs showed significant correlations with hybrid performance and heterosis for some yield traits, the determination coefficients were low. The results suggested that neither heterozygosities nor QTLs for yield traits were suitable to predict hybrid performance and heterosis in Brassica napus.     

山西省小杂粮生产病害防治现状评价

采用文献资料法和现场调查相结合的方法,研究了山西省小杂粮谷子、糜子、荞麦、莜麦、绿豆传统生产过程中的病害防治现状.结果表明,5种小杂粮的常见病害共23种,其中6种病害的化学防治中使用了绿色食品禁用药品,且大多数病害防治以化学防治为主.提出加强农业防治,优先物理防治,提倡生物防治,巧用化学防治,使其生产过程真正符合绿色食品生产的要求.并建议根据绿色食品病害防治要求,更新相关教材、专著病害防治内容.     

Analysis of wheat-Thinopyrum intermedium derivatives with BYDV-resistance

Chromosome compositions of seven lines, derived from hybrids between a wheat cultivar and the wheat-Thinopyrum intermedium addition line Z6, with barley yellow dwarf virus (BYDV) resistance, were determined by genomic in situ hybridization, cytogenetic and SSR assays. The results showed that line N522 was a disomic addition line, lines N420 and N439 were 2Ai-2(2B) chromosome substitution lines, lines N431 and N452 were 2Ai-2(2D) chromosome substitution lines, line N523 was a 2Ai-2S(2D) ditelosomic substitution line, and line N530 was a double ditelosomic line with the mitotic chromosome number of 2n = 40 + 4t. One pair of telosomes in line N530 lacked several proximal SSR markers of chromosome 2AS, but possessed certain terminal markers, which were consistent with an acrocentric structure, and the other pair of chromosome arms were presumably 2Ai-2S telosomes with BYDV-resistance. These wheat-Th. intermedium lines provide useful genetic resources for developing alien chromosome translocation lines.     

陆地棉品种抗黄萎病性状的分子标记及其辅助选择效果

利用综合性状优良、适应性广、抗黄萎病的鲁棉研22号与渐渗了海岛棉优异纤维基因的鲁原343组配杂交组合,对F2∶3家系在不同发病时期进行黄萎病鉴定,并以SSR标记对抗黄萎病性状进行定位分析.在棉花发病相对较轻的7月份检测到1个位点(qVWR-16-1a)与抗黄萎病有关;在发病较重的8月份,检测到3个QTLs位点与抗黄萎病有关,其中1个QTL(qVWR-16-1b)与7月份检测到的位点qVWR-16-1a为同一位点,能解释的表型变异为10.27%,与NAU751连锁较紧密,另外2个与BNL1395和BNL3590连锁较紧密的位点qVWR-16-2b、qVWR-2-1b,能解释的表型变异分别为10.8%和13.78%.利用检测到的与3个QTL位点连锁较紧密的SSR标记对杂交后代辅助鉴定,发现标记NAU751和BNL1395的抗性基因型均能显著增加后代的黄萎病抗性,两个标记的抗性基因型聚合后,后代抗性水平提高极显著.分子标记辅助抗病选择应用于优异纤维渐渗系杂交后代的鉴定中,可以培育出既优质又抗病的棉花新品种.     

宁南山区旱地玉米发展前景及效益分析

玉米在宁南山区的固原市栽培历史悠久．但由于品种老化、抗逆性差、产量低，长期以来受春夏之交低温干旱两大气候因素限制，发展十分缓慢。地膜覆盖种植技术的推广应用，有效地解决了两大灾害性气候的影响，玉米种植面积和单产都有了突破性发展．成为山区农业生产中一项推广最快、效益最高、增产幅度最大的农业实用技术。     

A Simple and Reliable Assay for Detecting Specific Nucleotide Sequences in Plants Using Optical Thin-film Biosensor Chips

Here we report the adaptation and optimization of an efficient, accurate and inexpensive assay that employs custom-designed silicon-based optical thin-film biosensor chips to detect unique transgenes in genetically modified （GM） crops and SN-P markers in model plant genomes. Briefly, aldehyde-attached sequence-specific singlestranded oligonucleotide probes are arrayed and covalently attached to a hydrazine-derivatized biosensor chip surface. Unique DNA sequences （or genes） are detected by hybridizing biotinylated PCR amplicons of the DNA sequences to probes on the chip surface. In the SN-P assay, target sequences （PCR amplicons） are hybridized in the presence of a mixture of biotinylated detector probes and a thermostable DNA ligase. Only perfect matches between the probe and target sequences, but not those with even a single nucleotide mismatch, can be covalently fixed on the chip surface. In both cases, the presence of specific target sequences is siL, nified by a color change on the chip surface （gold to blue/purple） after brief incubation with an anti-biotin IgG horseradish peroxidase （HRP） to generate a precipitable product from an HRP substrate.     

基于RF算法优选多时相特征的冬小麦空间分布自动解译

为探讨如何利用遥感影像自动解译技术,实现冬小麦种植情况统计调查、提高提取精度,选择冬小麦关键生育期6个时相的高分二号遥感影像数据,分别从6个时相的近红外灰度(NIR)、红波段灰度(R)、绿波段灰度(G)、蓝波段灰度(B)、比值植被指数(RVI)、归一化植被指数(NDVI) 6个特征中优选出对冬小麦面积提取最敏感的1个特征作为输入变量,每个时相选择1个特征,6个时相共选出6个特征作为输入变量,利用随机森林算法构建模型,提取冬小麦空间分布特征。选择研究区不同长势、不同种植品种的地块样本构建训练集,利用多时相特征构建模型,并将模型推广应用于整个大厂回族自治县,得到大厂回族自治县冬小麦的空间分布情况。通过与统计结果对比分析,经过多时相特征优选构建的模型对冬小麦的识别精度接近90%。经过样本优化和后期处理仍可提升精度,此方法能在保证提取精度的前提下对冬小麦进行快速提取,提高相应的工作效率。     

利用SSR标记区别小麦品种种子混杂和SSR位点不纯的研究

在用SSR标记检测小麦种子纯度时,种子混杂和SSR位点不纯都会造成株间SSR带型的差异,本文提出了SSR位点不纯的概念,并分析了存在这一现象的原因,指出这一现象普遍存在于小麦品种中。为此在检测小麦种子纯度时,需要注意区别种子混杂和SSR位点不纯,以免将SSR位点不纯造成的株间带型差异误认为是种子混杂,其原则是:(1)必须进行多个SSR位点的检测;(2)某单株的多个SSR位点的带型与被检测品种不同,可确认为混杂植株;(3)剔除混杂植株后,某单株的个别SSR位点的带型与被检测品种不同,将被认为是SSR位点不纯所致。