水稻加工品质数量性状基因座 (QTLs)分子定位研究

检测了Lemont/特青RI群体212个株系的糙米率（BR）,精米率（MR）和整精米率（HR）等3项加工品质性状,利用RFLP连锁图和线性模型的复合区间作图方法（QTLMapperV1.0)进行QTL定位研究。群体呈边境分布,双向超亲现象明显,HR较BR,MR变异范围更大并偏向低值方向;分别检测到1个MR,4个HR主效QTL,其中QHr6和QHr7等2个基因座具有较大遗传效应;分别检测到12对影响BR、5对影响MR,16对影响HR的上位性基因座,上位性效应的影响大于主效QTLs,不同性状或同一性状上位性效应通过共同的区间形成复杂的互相联系。     

水稻亚种间杂交粒重及加工品质性状的遗传效应分析

用4个广亲和粳型品种和5个籼型品种为材料,按NCⅡ设计配制杂交组合,获得同一环境下的亲本及F_1植株上的籽粒群体(F_2),对其稻谷千粒重、糙米千粒重、出糙率、总精米率以及整精米率等粒重和加工品质性状进行测定,并按胚乳性状遗传模型和混合线性模型的分析方法对籼粳亚种间杂交稻粒重及加工品质性状的遗传效应进行了研究,结果表明:籼粳交籽粒的粒重及各加工品质性状同时受到胚乳直接基因效应、母体基因效应以及微弱的细胞质效应的影响,但其主要受制于母体加性效应,并且存在一定的胚乳杂种优势和母体杂种优势;不同亲本品种对于粒重及加工品质性状的遗传改良具有不同的作用.     

Identification of Quantitative Trait Loci for Grain Appearance and Milling Quality Using a Doubled-Haploid Rice Population

Improving grain quality, which is composed primarily of the appearance of the grain and its cooking and milling attributes, is a major objective of many rice-producing areas in China. In the present study, we conducted a marker-based genetic analysis of the appearance and milling quality of rice （Oryza sativa L.） grains using a doubled-haploid population derived from a cross between the indica inbred Zhenshan 97 strain and the japonica inbred Wuyujing 2 strain. Quantitative trait locus （QTL） analysis using a mixed linear model approach revealed that the traits investigated were affected by one to seven QTLs that individually explained 4.0%-30.7% of the phenotypic variation. Cumulatively, the QTL for each trait explained from 12.9% to 61.4% of the phenotypic variation. Some QTLs tended to have a pleiotropic or location-linked association as a cause of the observed phenotypic correlations between different traits. Improvement of the characteristics of grain appearance and grain weight, as well as an improvement in the milling quality of rice grains, would be expected by a recombination of different QTLs using marker-assisted selection.     

粳稻品质性状间及其与植株性状和产量性状间的遗传相关

利用朱军等提出的种子性状遗传模型,采用 3×3 NCⅡ正反交设计的亲本和部分组合F2代种子,分析了品质性状糙米率、垩白粒率、垩白面积和AC间及上述品质性状与株高、穗部性状等的遗传相关,以期为粳稻育种后代选择提供指导。结果表明,精米重与糙米率存在极显著的母体加性相关;虽然控制品质性状的主要遗传效应分量与植株性状相应遗传效应分量遗传协方差不显著,但在其他相应遗传效应分量方面存在着复杂的关系。     

不同环境条件下粳型杂交稻米碾磨品质性状的遗传效应分析

采用包括基因型×环境互作效应的种子遗传模型,对粳型杂交稻稻米碾磨品质性状进行了遗传研究.结果表明:各碾磨品质性状除了受制于种子直接效应、细胞质效应和母体效应等遗传主效应外,还明显受到各基因型×环境互作效应的影响.其中糙米率性状以遗传主效应为主,而精米率、整精米率性状以基因型×环境互作效应为主.在遗传主效应中,糙米率性状主要受种子直接加性效应、母体加性效应的控制;在基因型×环境互作效应中,精米率和整精米率性状都是以种子直接加性×环境互作效应和母体加性×环境互作效应为主,细胞质×环境互作效应也起着较为重要的作用.大部分稻米碾磨品质性状的狭义遗传率均较高,其中糙米率性状以普通狭义遗传率为主,而精米率和整精米率性状则以互作狭义遗传率为主.另外,根据性状的遗传效应预测值对各亲本的育种利用价值作了评价.     

云南粳稻碾磨品质性状稳定性分析

利用AMMI模型对2年5点12个粳稻品种的糙米率、精米率和整精米率进行了稳定性分析,并以碾磨品质性状的表型值及其相应的稳定性参数(Di)为指标,对供试品种进行聚类分析和评价.结果表明,糙米率、精米率和整精米率在不同品种和环境间的差异以及品种×环境互作效应均达极显著水平;碾磨品质性状的稳定性随品种和环境不同而变化较大,其稳定性顺序为糙米率>精米率>整精米率.综合考虑糙米率、精米率和整精米率及其稳定性,云粳优14号、滇元1号、云粳18号和滇元2号的碾磨品质和稳定性好,可作育种亲本,以改良水稻品种的碾磨品质及其稳定性.     

Genome-Wide Association Study of Grain Appearance and Milling Quality in a Worldwide Collection of Indica Rice Germplasm

Grain appearance quality and milling quality are the main determinants of market value of rice. Breeding for improved grain quality is a major objective of rice breeding worldwide. Identification of genes/QTL controlling quality traits is the prerequisite for increasing breeding efficiency through marker-assisted selection. Here, we reported a genome-wide association study in indica rice to identify QTL associated with 10 appearance and milling quality related traits, including grain length, grain width, grain length to width ratio, grain thickness, thousand grain weight, degree of endosperm chalkiness, percentage of grains with chalkiness, brown rice rate, milled rice rate and head milled rice rate. A diversity panel consisting of 272 indica accessions collected worldwide was evaluated in four locations including Hangzhou, Jingzhou, Sanya and Shenzhen representing indica rice production environments in China and genotyped using genotyping-by-sequencing and Diversity Arrays Technology based on next-generation sequencing technique called DArTseq™. A wide range of variation was observed for all traits in all environments. A total of 16 different association analysis models were compared to determine the best model for each trait-environment combination. Association mapping based on 18,824 high quality markers yielded 38 QTL for the 10 traits. Five of the detected QTL corresponded to known genes or fine mapped QTL. Among the 33 novel QTL identified, qDEC1.1 (qGLWR1.1), qBRR2.2 (qGL2.1), qTGW2.1 (qGL2.2), qGW11.1 (qMRR11.1) and qGL7.1 affected multiple traits with relatively large effects and/or were detected in multiple environments. The research provided an insight of the genetic architecture of rice grain quality and important information for mining genes/QTL with large effects within indica accessions for rice breeding.     

杂交粳稻及其亲本千粒重与产量、品质的相关性

为了探明杂交粳稻及其亲本千粒重与产量、品质的关系,以4个千粒重介于23.1~28.0 g之间的BT型不育系和24个千粒重介于18.1~32.0 g之间的三系粳稻恢复系,采用p×q不完全双列杂交(NCⅡ)设计,配制96个杂交组合为试验材料,对F1千粒重优势表现、F1千粒重与亲本千粒重及其与产量、品质性状间的相关性进行分析,确定高产优质兼顾的杂交粳稻的千粒重范围。结果表明:(1)56.3%的杂交组合千粒重超过其双亲平均值,19.8%的杂交组合千粒重表现正向超亲优势;(2)F1千粒重与母本千粒重、父本千粒重、双亲千粒重平均值的相关性均达极显著水平(r=0.33**、0.71**、0.78**),且恢复系千粒重对杂种的影响大于不育系;(3)F1千粒重、父本千粒重及双亲千粒重平均值与组合单株产量的相关性均达极显著水平(r=0.55**、0.47**、0.51**),母本千粒重与组合单株产量相关不显著;(4)F1千粒重、父本千粒重与糙米率、精米率、整精米率、垩白粒率、粒长、粒宽均呈极显著正相关,与透明度呈显著正相关,母本千粒重与垩白粒率、垩白度、粒长均呈极显著正相关,与粒宽呈显著正相关;(5)杂交粳稻育种中具有高产优质兼顾的F1千粒重范围应在25.1~27.0 g之间。     

Radial Oxygen Losses from Intact Rice Roots as Affected by Distance from the Apex, Respiration and Waterlogging

Radial oxygen losses (ROL) from the roots of intact rice plants were assayed by the cylindrical Pt electrode technique. At 23°C losses from roots grown in waterlogged soil proved to be about double those from non-waterlogged plants. Cooling which lowers respiratory activity led to increased ROL and it was estimated that at 23°C respiratory activity had been reducing oxygen loss by 8 to 10 10^–8g O₂ cm^–2 root surface min^–1 (c. 50 %) in the non waterlogged, and by 4.5 to 5.5 10^–8g O₂ cm^–2 min^–1 (2C–30 %) in the waterlogged roots. Lacunae formation occurred nearer to the apex and was eventually more extensive in the waterlogged roots while the presence of more intact and presumably functional tissue in the non-waterlogged roots coincides with the greater respiratory effect noted. Estimated flux rates at 23°C (respiration inactive) were respectively 15–17 × 10^–8g O₂ cm^–2 min^–1 (non-waterlogged) and 20–23 × 10^–8g O₂ cm^–2 min^–1 (waterlogged). A major part of this difference can probably be accounted for directly by the differences in root porosity, and Meakiness' superimposed upon lower porosity in the non-waterlogged plants may account for the remainder. ROL was also examined in relation to distance from the apex. With respiratory activity lowered by cooling, two patterns of oxygen loss were detected. Pattern I was a property of younger roots of length between 5–9 cm, while pattern 2 was found in longer roots 11–16 cm bearing numerous emergent laterals. In both, ROL fell rapidly towards the base and at 4–5 cm approached zero in pattern 1 and near zero to about 16% of the maximum in pattern 2. The rapid drop in oxygen loss in both patterns which indicates a concomitant decrease in root wall permeability was associated with the appearance of cortical lacunae at 2–3 cm from the apex. In pattern 2 a rise in ROL began at 5–6 cm from the apex. The presence of lateral root initials in both the pericycle and unbroken segments of cortex was associated with maintained permeability in this pattern as well as with the basal increase in ROL. With a 3-electrode system placed around the apical 3 cm regions of waterlogged roots, it was found that ROL was substantially affected by respiratory activity at 0.5 cm, a little less so at 1.7 cm, but much less or not at all at 3 cm from the apex. The drop in respiratory effect parallelled the formation of cortical lacunae.     

害虫密度与作物产量损失预测的一种新方法

本文首次引入幂指模型（y=yLMexp(-bd^α）来模拟害虫密度与作物产量间的关系。通过对15组不同来源的害虫与作物竞争资料的模拟,证明幂指模型具有实际性的生物学意义,能准确地描述多种害虫和多种作物间的危害关系,预测害虫危害作物可能造成的产量损失,为害虫的经济防治提供了一种新的研究方法。     

Methyl Jasmonate Reduces Grain Yield by Mediating Stress Signals to Alter Spikelet Development in Rice

Jasmonic acid (JA) is involved in plant development and the defense response. Transgenic overexpression of the Arabidopsis (Arabidopsis thaliana) jasmonic acid carboxyl methyltransferase gene (AtJMT) linked to the Ubi1 promoter increased levels of methyl jasmonate (MeJA) by 6-fold in young panicles. Grain yield was greatly reduced in Ubi1:AtJMT plants due to a lower numbers of spikelets and lower filling rates than were observed for nontransgenic (NT) controls. Ubi1:AtJMT plants had altered numbers of spikelet organs, including the lemma/palea, lodicule, anther, and pistil. The loss of grain yield and alteration in spikelet organ numbers were reproduced by treating NT plants with exogenous MeJA, indicating that increased levels of MeJA in Ubi1:AtJMT panicles inhibited spikelet development. Interestingly, MeJA levels were increased by 19-fold in young NT panicles upon exposure to drought conditions, resulting in a loss of grain yield that was similar to that observed in Ubi1:AtJMT plants. Levels of abscisic acid (ABA) were increased by 1.9- and 1.4-fold in Ubi1:AtJMT and drought-treated NT panicles, respectively. The ABA increase in Ubi1:AtJMT panicles grown in nondrought conditions suggests that MeJA, rather than drought stress, induces ABA biosynthesis under drought conditions. Using microarray and quantitative polymerase chain reaction analyses, we identified seven genes that were regulated in both Ubi1:AtJMT and drought-treated NT panicles. Two genes, OsJMT1 and OsSDR (for short-chain alcohol dehydrogenase), are involved in MeJA and ABA biosynthesis, respectively, in rice (Oryza sativa). Overall, our results suggest that plants produce MeJA during drought stress, which in turn stimulates the production of ABA, together leading to a loss of grain yield.     

Moderate Salinity Stress Reduces Rice Grain Yield by Influencing Expression of Grain Number- and Grain Filling-Associated Genes

Journal of Plant Growth Regulation - Soil salinity is an environmental stress severely impacting on rice grain yield. However, limited information is available on how salinity affects expression...     

水稻籽粒激素对产量和品质的调控效应研究进展

水稻籽粒激素含量甚微,却能有效调控产量与品质的形成。该文主要对近年来国内外有关水稻籽粒中激素(IAA、GA1+4、Z、ZR、iPA、ABA、ETH)含量在不同环境下的变化规律、各激素及其互作对水稻籽粒产量和品质性状的调控效应和调控机理进行综述,并讨论了该领域未来的研究重点和方向,为今后相关研究提供信息参考。     

Selective Plating Underestimates Abundance and Shows Differential Recovery of Bifidobacterial Species from Human Feces

The aim of the present work was to compare the efficacies and levels of selectivity of different culture-dependent and -independent methods for analyzing bifidobacteria in human stool samples. The three different culture media used here significantly differed from each other, particularly with regard to the recovery of Bifidobacterium adolescentis. Bifidobacterium medium failed to recover B. adolescentis; Beerens medium recovered some B. adolescentis organisms (17% of total bifidobacteria), whereas tomato-Eugon medium recovered mainly B. adolescentis organisms (58% of total bifidobacteria). A culture-independent method that combines GC fractionation of bacterial community DNA and 16S rRNA sequencing indicated that B. adolescentis organisms accounted for 85% of all bifidobacteria. Methodological biases, such as those described in this paper, should be taken into account in interpreting earlier studies and designing future experiments.     

浙江天台山七子花种群结构与分布格局研究

浙江天台山七子花种群结构与分布格局研究金则新（台州师范专科学校,浙江临海３１７０００）ＡＳｔｕｄｙｏｆＰｏｐｕｌａｔｉｏｎＳｔｒｕｃｔｕｒｅａｎｄＤｉｓｔｒｉｂｕｔｉｏｎＰａｔｅｒｎｏｆＨｅｐｔａｃｏｄｉｕｍｍｉｃｏｎｉｏｉｄｅｓｉｎｔｈｅＴｉａｎｔ...     

Effect of Simultaneous Water Deficit Stress and Meloidogyne incognita Infection on Cotton Yield and Fiber Quality

Both water deficit stress and Meloidogyne incognita infection can reduce cotton growth and yield, and drought can affect fiber quality, but the effect of nematodes on fiber quality is not well documented. To determine whether nematode parasitism affects fiber quality and whether the combined effects of nematode and drought stress on yield and quality are additive (independent effects), synergistic, or antagonistic, we conducted a study for 7 yr in a field infested with M. incognita. A split-plot design was used with the main plot factor as one of three irrigation treatments (low [nonirrigated], moderate irrigation, and high irrigation [water-replete]) and the subplot factor as 0 or 56 l/ha 1,3-dichloropropene. We prevented water deficit stress in plots designated as water-replete by supplementing rainfall with irrigation. Plots receiving moderate irrigation received half the water applied to the water-replete treatment. The severity of root galling was greater in nonfumigated plots and in plots receiving the least irrigation, but the amount of irrigation did not influence the effect of fumigation on root galling (no irrigation × fumigation interaction). The weights of lint and seed harvested were reduced in nonfumigated plots and also decreased as the level of irrigation decreased, but fumigation did not influence the effect of irrigation. Nematodes affected fiber quality by increasing micronaire readings but typically had little or no effect on percent lint, fiber length (measured by HVI), uniformity, strength, elongation, length (based on weight or number measured by AFIS), upper quartile length, or short fiber content (based on weight or number). Micronaire also was increased by water deficit stress, but the effects from nematodes and water stress were independent. We conclude that the detrimental effects caused to cotton yield and quality by nematode parasitism and water deficit stress are independent and therefore additive.     

增效位点在稻米碾磨品质分子预测中的效应及其与遗传效应的关系

利用重庆和泸州两个环境下种植的两套杂交水稻不完全双列组合（按NCII设计）,结合SSR和AFLP标记,按照单向分组的方差分析法筛选与凡碾磨品质表现相关的阳性位点和增效位点,分别就此两类位点建立相应的预测模型,同时采用包括基因型×环境互作效应的种子遗传模型对这两套材料进行遗传效应分析,旨在分析水稻碾磨品质的分子预测效果及其与遗传效应之间的关系．结果表明：（1）增效预测模型较阳性预测模型稳定性好,精确度高．糙米率、精米率和整精米率的增效预测模型可决系数分别为0．6467、0．6516和0．7265,而阳性预测模型则为0．4053、0．4981和0．6897;增效预测模型的剩余平方和分别为0．8104、0．8011和4．4508,而阳性预测模型则为0．9826、0．9673和6．2676;增效预测模型的预测变异系数为6．79％、7．27％和5．02％,而阳性预测模型则为9．12％、8．13％和6．09％．（2）增效预测模型预测效果因材料和性状的不同存在差异,套内预测好于套间预测,固定不育系预测好于固定恢复系预测;预测效果以整精米率最好,精米率次之,糙米率稍差;（3）不同性状和材料自々预测效果受环境互作自々影响不同,糙米率受环境互作影响大干精米率大干整精米率．因此,可根据不育系和恢复系材料特性,在一定环境条件下建立碾磨品质性状的预测模型,或者选择遗传主效应表现良好,同时环境互作效应表现较为稳定的亲本建立预测模型,可能将会获得较为理想的预测效果．     

抽穗扬花期高温胁迫对水稻主要品质指标的影响

高温热害对水稻生产造成了巨大的损失。利用国际水稻研究所耐热圃材料,在抽穗扬花期进行高温处理,研究了该时期高温胁迫对水稻主要品质评价指标的影响,结果如下：水稻耐热圃材料的耐热性有较大的差别,依然存在高温相对敏感材料;抽穗扬花期高温胁迫对水稻主要品质评价指标影响较大;高温胁迫对水稻籽粒的透明度、长宽比、垩白率、糊化温度和蛋白质含量等品质指标与品种的耐热性相关关系不大;高温胁迫下直链淀粉含量变化与品种耐热系数表现出显著的正相关关系（r=0.659 78）;高温胁迫下胶稠度变化与不同水稻品种的耐热系数呈显著的负相关关系（r=-0.516 70）。