甜瓜白粉病抗性基因的遗传与分子标记

为了建立甜瓜抗白粉病基因的分子标记辅助选择方法,以杂交组合1A151/恒进红瓤酥的6个世代群体 P1,P2,F1,F2,BCr和BCs为材料,利用风媒接种方法和分群法,研究了抗病基因的遗传和分子标记。结果表明,抗源 1A151对白粉病菌的抗性由1对不完全显性抗病基因控制,并寻找到了1个与抗病基因位点连锁的分子标记RAPD- S329,其距离为6.81±1.67个遗传单位。     

Detection of race 1 strains of <Emphasis Type="Italic">Ralstonia solanacearum</Emphasis> in field samples in Taiwan using a BIO-PCR method

Bacterial wilt caused by race 1 strains of Ralstonia solanacearum is endemic on tomato produced in diverse agro-ecosystems in Taiwan. Using a new BIO-PCR protocol developed in this study, R. solanacearum was detected in soil, weed, and water samples collected from eight fields with different disease histories and cropping systems located in major tomato production areas. The sensitivity of the BIO-PCR was 1.9 CFU ml⁻¹ and 17 CFU g⁻¹ of soil for pure suspension and infested soil, respectively. The positive detection frequency of the BIO-PCR method was 66.6, 39.6, 23.1, and 31.8% for all tested samples of soil, weed rhizosphere soil, weed root, and water, respectively, and was higher than plating on MSM-1 medium. Detection of R. solanacearum from field soil indicated that spatial distribution of the pathogen in the field was not even regardless of the presence or absence of the disease and the different agro-ecosystems where the sampled fields were located, and the degree of unevenness was higher when tomato was absent from the field. Weed rhizosphere soils could be good sampling targets to monitor the pathogen in the field, because a higher positive detection proportion and population of R. solanacearum were found in the rhizosphere rather than the root of the collected weed samples. Symptomless weeds and contaminated irrigation, standing, or drainage waters were found to be important for the over-season survival and dissemination of R. solanacearum.     

柱花草分子标记的研究进展

综述近年来RFLP、RAPD、SSR及AFLP等几种分子标记在柱花草育种上的应用，以及分子标记在辅助育种和抗病基因定位方向的研究进展。     

犬乳腺癌预后分子标记的筛选

为了获得犬乳腺癌转移早期的分子标记,比较了27个淋巴结转移/不转移犬乳腺癌样本的基因芯片数据,获得了775个差异表达基因,并用Cox比例风险模型进行基因表达的单因素分析得到38个与生存显著相关的基因.在此基础上用惩罚Cox模型对样本进行生存预测,得到10个基因的分类器,可以比较准确预测样本的预后风险,准确率可达到92.3％.这些基因与雌激素代谢、细胞分化、转录等生物学过程相关,可能为犬乳腺癌预后分子标记和治疗靶标,这将给犬乳腺癌的临床诊断和治疗提供新的思路.     

Impact of genomics on the study of plant nutrition. 7. Practical use of naturally occurring genomic variation in plant nutrition

(Jpn. J. Soil Sci.Plant Nutr., 77, 343–349, 2006)     

Use of Myxococcus xanthus protoporphyrinogen oxidase as a selectable marker for transformation of rice

Protoporphyrinogen oxidase (PPO) is the target enzyme of peroxidizing herbicides. The overexpression of Myxococcus xanthus PPO (Mx PPO) confers a high level of herbicide resistance in rice. Among the peroxidizing herbicides, butafenacil has an efficiency ∼1000-fold that of oxadiazon, as judged by calli susceptibility tests upon herbicide treatment. Butafenacil (0.1 μM) was used to select transgenic rice plants expressing Mx PPO under the control of the constitutive maize ubiquitin promoter. The ectopic expression of the Mx PPO transgene was investigated in the T₀ generation by Northern blot and Western blot analysis. The T₀ transgenic plants expressing the Mx PPO gene were resistant to butafenacil based on in vitro leaf disk and in vivo foliar spray tests.     

Development of AS‐PCR marker based on a key mutation confirmed by resequencing of Wx‐mp in Milky Princess and its application in japonica soft rice (Oryza sativa L.) breeding

Soft rice with low amylose content (AC) ranging by 5–15% is a unique type with special eating and appearance quality and has become popular in the rice market. We resequenced the Wx‐mp, a key allele from Milky Princess, a Japanese low AC variety, and found that the +473 mutation in exon 4 is the key mutation in both Wx‐mp and its ancestor allele, Wx‐mq from Milky Queen. Based on this functional mutation, an allele‐specific PCR (AS‐PCR) marker was developed and proven in a breeding population derived from a cross between a Chinese late variety Nan Keng 46 (Wx‐mp/Wx‐mp) and an early line Ning 63121(Wx‐b/Wx‐b). Based on the marker‐aided selection by our newly developed AS‐PCR marker for Wx‐mp and the known ST10 marker for Stvb‐i, a total of 12 Wx‐mp homozygotes were selected from 198 F₂ progenies, and four of them were immune to rice stripe virus (RSV) with averagely 11.3 days earlier heading than Nan Keng 46 without significant change in grain yield.     

QTL for popping characteristics in popcorn

Popping volume (PV), flake size (FS) and popping rate (PR) are three important popping characteristics in popcorn ( Zea mays L.). We developed 259 F_2:3 lines from a cross between a dent corn inbred 'Dan232' and a popcorn inbred 'N04' that were grown during spring and summer to evaluate the three popping characteristics. Fifteen quantitative trait loci (QTL) were detected on chromosomes 1, 2, 5, 6, 7 and 8 using composite interval mapping. The numbers of QTL were 6, 4 and 5 for PV, FS and PR, respectively, with phenotypic variance explained ranging from 4.9% to 15.6% for a single QTL, accounting for a total of 54.0%, 34.5% and 39.1% of the total phenotypic variance respectively. Partially dominance and overdominance effects played an important role in popping characteristics. Only 13 pairs of digenic interactions were detected. The QTL on chromosome bin 1.05–1.06 for PV and PR, and 5.07 for FS were in accordance with previous reports and could be good candidate QTL for marker-assisted selection. There was a significant correlation amongst QTL on chromosomes 1, 6 and 8 for PV and PR.     

3D打印技术在手机上盖制造中的应用

在介绍3D打印技术的基本原理、形成及发展概况基础上,重点介绍其典型成型工艺方法：选择性激光烧结（SLS）。并以手机上盖为例,分析了运用SLS工艺加工样品的流程,并指出了网络化、标准化是该项技术今后的发展方向。