Genetic Analysis of Leaf Length and Leaf Width in Bitter Gourd

[Objectives]To explore the genetic mechanism that leaf length and leaf width in bitter gourd has realistic guiding significance for formulating breeding strategy.[Methods]In this paper,the cross was made between CN19-1 and Thai4-6 and an F2segregation population was constructed.The genetic characteristics of leaf length and leaf width were analyzed by employing the major gene plus polygene mixed genetic model.[Results]The data analysis results demonstrated that the leaf length and leaf width of the F_(2) segregation population showed continuous distribution.The optimum model for leaf length genetic analysis was A-1,the additive effect value of the major gene was 3.1766,the dominant effect value was-3.1766,and the heritability was 74.51%.The optimum model for leaf width genetic analysis was B-1.The additive effect values of 2 pairs of major genes controlling the leaf width were 3.1917 and 0.9623,respectively.The dominant effect values were-1.3135 and-0.3463,respectively.The additive×additive interaction effect was-0.3591,the additive×dominant interaction effect was-0.2570,the dominant×additive interaction effect was 1.9916,the dominant×dominant interaction effect was 1.9686.The heritability of major genes was 96.67%.[Conclusions]This study is expected to provide a theoretical basis for the breeding of bitter gourd.

OsSRK1,an Atypical S-Receptor-Like Kinase Positively Regulates Leaf Width and Salt Tolerance in Rice

Receptor-like kinases(RLKs)are important for plant growth,development and defense responses.The S-receptor protein kinases(SRKs),which represent an RLK subfamily,control the selfincompatibility among Brassica species.However,little information is available regarding SRK functions in rice.We identified a gene OsSRK1 encoding an atypical SRK.The transcript of OsSRK1 was induced by abscisic acid(ABA),salt and polyethylene glycol.OsSRK1 localized to the plasma membrane and cytoplasm.Leaf width was increased in OsSRK1-overexpression(OsSRK1-OX)transgenic rice plants,likely because of an increase in cell number per leaf.Furthermore,the expression levels of OsCYCA3-1 and OsCYCD2-1,which encode positive regulators of cell division,were up-regulated in leaf primordium of OsSRK1-OX rice plants relative to those in wild type.Meanwhile,the expression level of OsKRP1,which encodes cell cycle inhibitor,was down-regulated in the OsSRK1-OX plants.Therefore,it is deduced that OsSRK1 regulates leaf width by promoting cell division in the leaf primordium.Additionally,OsSRK1-OX plants exhibited enhanced ABA sensitivity and salt tolerance compared with wild type.These results suggest that OsSRK1 plays important roles in leaf development and salt responses in rice.

Allometric models for leaf area and leaf mass predictions across different growing seasons of elm tree(Ulmus japonica)

Convenient and effective methods to determine seasonal changes in individual leaf area (LA) and leaf mass (LM) of plants are useful in research on plant physiology and forest ecology. However, practical methods for estimating LA and LM of elm (Ulmus japonica) leaves in different periods have rarely been reported. We collected sample elm leaves in June, July and September. Then, we developed allometric models relating LA, LM and leaf parameters, such as leaf length (L) and width (W) or the product of L and W (LW). Our objective was to find optimal allometric models for conveniently and effectively estimating LA and LM of elm leaves in different periods. LA and LM were significantly correlated with leaf parameters (P < 0.05), and allometric models with LW as an independent variable were best for estimating LA and LM in each period. A linear model was separately developed to predict LA of elm leaves in June, July and September, and it yielded high accuracies of 93, 96 and 96%, respectively. Similarly, a specific allometric model for predicting LM was developed separately in three periods, and the optimal model form in both June and July was a power model, but the linear model was optimal for September. The accuracies of the allometric models in predicting LM were 88, 83 and 84% for June, July and September, respectively. The error caused by ignoring seasonal variation of allometric models in predicting LA and LM in the three periods were 1-4 and 16-59%, respectively.

Correlation of Leaf and Root Senescence During Ripening in Dry Seeded and Transplanted Rice

Dry seeding is a resource-saving rice establishment method. With an equivalent yield, dry seeded flooded rice （DSR） has been considered as a replacement for traditional transplanted flooded rice （TFR）. However, the differences in leaf and root senescence during grain filling between DSR and TFR were seldom identified. In this study, the root length, root tip number and leaf senescence of rice varieties Huanghuazhan and Yangliangyou 6 during ripening were compared between DSR and TFR. Results showed that top three leaves in DSR had the characteristics of relatively lower SPAD value, lower N content and premature leaf senescence. In addition, both the total root length and total root tip number of DSR were significantly lower than those of TFR. In conclusion, premature and quick leaf senescence was related with inadequate root length and root tip number during ripening, which might result from the deficiency of nitrogen supply in DSR. Techniques on improving leaf nitrogen status and delaying the leaf senescence during grain-filling in DSR should be developed in future researches.

Dosimetric evaluation of VMAT radiation therapy technique for breast cancer after conservative surgery based on three different types of multileaf collimators

Objective Radiotherapy combined with conservative surgery plays an important role in the treatment of early-stage breast cancer. Volumetric modulated arc therapy(VMAT) has been introduced into clinical practice. The purpose of this study was to investigate the dosimetric effects of different multileaf collimators(MLC) on VMAT radiotherapy plans for treating breast cancer.Methods Fifteen breast cancer patients who were treated using a conventional technique in our department were selected to participate in this retrospective analysis. VMAT plans based on three types of Elekta MLCs [Beam Modulator(BM) with 4-mm leaf width, Agility with 5-mm leaf width and MLCi2 with 10-mm leaf width] were independently generated for each patient. Plan comparisons were performed based on dose-volume histogram(DVH) analysis including dosimetric parameters such as the homogeneity index(HI), conformity index(CI), Dmax, Dmin, and Dmean for the planning treatment volume(PTV), in addition to dose-volume parameters for the organs at risk(OARs). The delivery efficiency of the three types of MLCs was compared in terms of the beam delivery time and the monitor units(MUs) per fraction for each plan. Results Both target uniformity and conformity were improved in plans for Agility and BM MLC compared with the plan using MLCi2. The mean HI decreased from 1.14 for MLCi2 to 1.13 for BM and 1.10 for Agility, while the mean CI increased from 0.68 for MLCi2 to 0.73 for BM and 0.75 for Agility. Furthermore, at both low and high dose levels, smaller volumes of ipsilateral lung, heart, contralateral lung, and breast were irradiated with Agility MLC than with the other two types of MLCs. The delivery time with Agility MLC was reduced by 10.8% and 32.1%, respectively, compared with that for MLCi2 and BM.Conclusion Our results indicate that the Agility MLC exhibits a dosimetric advantage and a significant improvement in delivery efficiency for the treatment of breast cancer using VMAT.

A New Disease of Cherry Plum Tree with Yellow Leaf Symptoms Associated with a Novel Phytoplasma in the Aster Yellows Group

A novel phytoplasma was detected in a cherry plum（Prunus cerasifera Ehrh） tree that mainly showed yellow leaf symptom. The tree was growing in an orchard located in Yangling District, Shaanxi Province, China. The leaves started as chlorotic and yellowing along leaf minor veins and leaf tips. Chlorosis rapidly developed to inter-veinal areas with the whole leaf becoming pale yellow in about 1-4 wk. Large numbers of phytoplasma-like bodies（PLBs） were seen under transmission electron microscopy. The majority of the PLBs was spherical or elliptical vesicles, with diameters in range of 0.1-0.6 μm, and distributed in the phloem cells of the infected tissues. A 1 246-bp 16 S ribosomal RNA（rRNA） gene fragment was amplified from DNA samples extracted from the yellow leaf tissues using two phytoplasma universal primer pairs R16mF2/R16mR1 and R16F2n/R16R2. Phylogenetic analysis using the 16 S rRNA gene sequence suggested that the phytoplasma associated with the yellow leaf symptoms belongs to a novel subclade in the aster yellows（AY） group（16SrI group）. Virtual and actual restriction fragment length polymorphism（RFLP） analysis of the 16 S rRNA gene fragment revealed that the phytoplasma was distinguishable from all existing 19 subgroups in the AY group（16SrI） by four restriction sites, Hinf I, Mse I, Sau3 A I and Taq I. The similarity coefficients of comparing the RFLP pattern of the 16 S rRNA gene fragment of this phytoplasma to each of the 19 reported subgroups ranged from 0.73 to 0.87, which indicates the phytoplasma associated with the cherry plum yellow leaf（CPYL） symptoms is probably a distinct and novel subgroup lineage in the AY group（16SrI）. In addition, the novel phytoplasma was experimentally transmitted to periwinkle（Catharanthus roseus） plants from the tree with CPYL symptoms and then back to a healthy 1-yr-old cherry plum tree via dodder（Cuscuta odorata） connections.

Leaf Wand for Measuring Chlorophyll Fluorescence on Cylindrical Leaves and Its Application on <i>Juncus roemerianus</i>(Black Needlerush)

Chlorophyll fluorescence is a well established technique to rapidly and non-invasively determine photosynthesis parameters in plant leaves. It can be used in both laboratory and field settings, and frequently dark-adaptation of a leaf sample is called for. In the field, this can be accomplished on flat leaves using standard leaf clips supplied by instrument manufacturers. However, not all plant leaves are flat, many are cylindrical or otherwise three-dimensional in shape. The standard leaf clip does not close fully on three-dimensional leaves, therefore, does not allow the sample to be properly dark adapted in the field. A new leaf “wand” was developed that can be slipped over an entire cylindrical leaf or culm of rushes and sedges for both light- and dark-adapted measurements. This new leaf wand is compared to the standard leaf clip (DLC-8) using a Walz mini-PAM on Juncus roemerianus(Black needlerush). Results indicate that dark-adapted yield measurements are not significantly different between leaf clips, while light-adapted yields are higher with the leaf wand. The potential sources of difference in the optical path of the excitation light and fluorescence return are discussed and compared between leaf clips. Construction of specialized leaf wands should be considered for any leaves are not flat and therefore that do not fit the standard leaf clip for complete dark-adaptation under field conditions.

Interactive Effects of Elevated [CO₂] and Soil Water Stress on Leaf Morphological and Anatomical Characteristic of Paper Birch Populations

The leaf morphological and stomatal characteristics of four paper birch (Betula papyrifera Marsh) populations, grown at four treatment conditions of carbon dioxide [CO2] and soil water levels were investigated to determine whether future increases in atmospheric [CO2] and water deficit affected the leaf characteristics. The populations from Cussion Lake, Little Oliver, Skimikin and Wayerton were grown for 12 weeks under ambient (360 ppm) and elevated (720 ppm) [CO2] at both high and low water levels. The populations significantly differed in leaf area and stomatal characteristics due to the interaction effects of [CO2], water levels and population differences. Most leaf morphological characteristics and stomatal density varied due to the effects of [CO2] and/or populations, but not due to the effect of water levels. Although elevated [CO2] alone barely affected stomatal area of the birch populations, simultaneous elevated [CO2] at both water levels had stimulated stomatal characteristics within and among the populations. Overall, elevated [CO2] reduced leaf area and increased stomatal density;and low water level resulted in smaller stomatal area, pore area and guard cell width. However, the populations responded differently to an increase in [CO2] and water levels. All populations showed plastic responses with respect to [CO2] and water levels either by decreasing stomatal area under low water level or by increasing stomatal density under elevated [CO2]. Hence, integration between and within leaf characteristics had helped paper birch populations maintain balance between [CO2] gain and water loss.

不同叶长·叶宽和单叶重对广元烤后烟叶质量的影响

为明确广元优质烤后烟叶适宜的叶长、叶宽和单叶重范围,为广元地区生产优质烤烟提供数据支撑,2021年在四川省广元市剑阁县5个收购线分别挑选10户种植水平具有代表性的烟农,取X2F、C2F、C3F和B2F等级烟叶样品各2 kg,按等级划分不同叶长、叶宽和单叶重进行烟叶质量评价。结果表明:随着叶长的增加,X2F、B2F等级烟叶总糖、还原糖含量呈减少趋势。随着叶长的增加,C3F烟叶烟碱、钾含量升高;随着叶宽的增加,C3F烟叶总糖、还原糖含量逐渐增加。X2F和C3F等级烟叶随着单叶重的增加,总糖含量逐渐增加,钾含量减少。随着烟叶叶宽和单叶重的增加,X2F烟叶外观质量总分均表现为先增加后降低。随着叶长的增加,C2F和C3F烟叶外观质量总分均表现为逐渐增加,外观质量总分从高到低依次为>75 cm、>65~75 cm、>55~65 cm、≤55 cm。随着叶长、叶宽和单叶重的增加,C2F、C3F、B2F烟叶感官质量得分大多表现为先上升后下降。随着叶长、叶宽的增加,C2F、B2F烟叶感官质量得分表现为先上升后下降。当X2F烟叶叶长控制在>50~60 cm、叶宽控制在>15~19 cm、单叶重控制在>7~11 g时,X2F烟叶综合品质较好;当C2F烟叶叶长控制在>55~65 cm、叶宽控制在>15~23 cm、单叶重控制在>9~13 g时,C2F烟叶综合品质较好;当C3F烟叶叶长控制在>65~75 cm、叶宽控制在>15~23 cm、单叶重控制在>8~12 g时,C3F烟叶综合品质较好;当B2F叶长控制在>55~65 cm、叶宽控制在>15~23 cm、单叶重控制在>9~15 g时,B2F烟叶综合品质较好。

烤烟品种K326上部叶烤后单叶重与感官质量的关系

为探索张家界市上部烟适宜的单叶重,以主栽品种K326为研究对象,设置不同单叶重区间,分析了单叶重与烟叶主要物理特性及感官质量的关系,确定了适宜的单叶重。结果表明:综合各单叶重对烟叶物理性状、感官质量的影响可知,高峰试验点单叶重为8~10、>10~12、>12~14 g时均表现较优,江垭试验点单叶重为8~10、>10~12 g时上部叶质量较好,可用性较高。根据叶长与单叶重的相关性,得出张家界烟区适宜的叶长区间:高峰试验点可将上部叶叶长在51.25~67.82 cm的占比、江垭试验点可将上部叶叶长在51.21~63.13 cm的占比作为技术调控目标。

全基因组关联分析(GWAS)鉴定水稻氮素利用效率候选基因

【目的】挖掘水稻氮高效的种质和基因资源,揭示其分子机制和遗传效应,是当前水稻氮素利用效率(NUE)研究的重要内容和目标。【方法】为了鉴定与水稻NUE相关的变异位点和候选基因,我们收集了190份亚洲稻为关联群体,通过质量过滤和群体频率过滤筛选出3,934,195个高质量的单核苷酸多态性(SNPs)位点,在大田条件下设置低氮(N_(1),90kg/hm^(2))和常规氮(N_(2),180kg/hm^(2))水平,成熟期调查水稻剑叶叶宽在低氮和常规氮处理下的表型数据,结合FarmCPU和MLM模型进行全基因组关联分析(GWAS)。【结果】通过植株在不同氮水平下的叶宽表型数据,计算该群体在低氮和常规氮水平下的剑叶宽表型比值Q(N_(1)/N_(2)),Q值呈现正态分布的特征。对Q值进行全基因组关联分析,在12条染色体上共鉴定了100个显著位点,确定了39个候选QTLs,包括已克隆NUE相关基因OsNR1.2和OsNAC42。进一步鉴定了候选基因OsNR1.2和OsNAC42的优异单倍型和潜在的优势单倍型组合,为水稻NUE的改良提供了有价值的资源和信息。【结论】利用GWAS和单倍型分析,揭示了水稻剑叶叶宽在不同氮处理下的遗传基础,鉴定了与NUE相关的候选QTLs和基因,包括OsNR1.2和OsNAC42。通过组合单倍型分析,鉴定了两个基因的优势单倍型组合,为水稻NUE的改良提供了有价值的资源和信息。

基于实例分割技术的草莓叶龄及冠幅表型快速提取方法

[目的/意义]为解决高通量草莓叶龄及冠幅提取问题,提出一种基于移动式表型平台和实例分割技术的高通量表型提取方法。[方法]利用小型移动式表型平台对温室内盆栽草莓植株的俯拍图像进行数据获取,并利用改进型Mask R-CNN(Convolutional Neural Network)模型对图像进行处理,以此获取草莓植株叶龄信息。首先利用带有分组注意力模块的Split-Attention Networks(ResNeSt)骨干网络替换原有网络,从而提高图像特征信息提取精度和执行效率。在训练时,利用Mosaic方法对草莓图像进行数据增强,并且使用二元交叉熵损失函数对原本的交叉熵分类损失函数进行优化,以达到更好的植株与叶片的检测准确度。在此基础上,对训练结果进行后处理,利用标定比值对冠幅进行计算。[结果和讨论]该方法能够在ResNeSt-101骨干网络下,实现80.1%的掩膜准确率和89.6%的检测框准确率,并且能够以99.3%的植株检测正确率和98.0%的叶片数量检出率实现高通量的草莓叶龄估算工作。而模型推理后草莓植株南北和东西向冠幅测试值与真实值相比误差均低于5%的约占98.1%。[结论]该方法有着较高的鲁棒性,能够为智慧农业下高通量植物表型获取与解析工作提供技术支持。

蔗叶还田对红壤薄土坡耕地坡面侵蚀过程阻控机制研究

基于广西红壤区保护性耕作的实际,在不同甘蔗叶覆盖方式下,对不同蔗叶长度和蔗叶量条件下坡耕地侵蚀过程与特征进行分析,研究不同蔗叶覆盖特征对坡耕地减流减沙效益的影响。结果表明:不同的蔗叶覆盖方式、蔗叶长度和蔗叶覆盖量对坡面减流减沙效益的影响都达到了极显著的水平(P<0.05),对减流减沙效益贡献最大的因素是蔗叶覆盖量。蔗叶表土覆盖条件下减流效果较好,蔗叶混合覆盖条件下减沙效果较好。蔗叶表土覆盖条件下减流减沙比(R_(rs))大小随着蔗叶覆盖量的增加呈现先减小后增加的趋势,蔗叶表土覆盖条件下的减沙水代价明显大于蔗叶混合覆盖。

一种新型航空发动机涡轮叶片叶冠啮合面的修复技术

以一种新型航空发动机涡轮叶片叶冠的修复过程为实例,对其修复过程进行了分析,对修复过程中存在的问题及解决方法进行了论述,对修复过程所用夹具、测具进行了简单介绍,优化了包含热加工和冷加工的工艺过程参数,成功完成了新型叶片的叶冠修复。

不同工厂化穴盘育苗条件对茶苗生长影响研究

通过对比试验探究在工厂化育苗条件下,扦插基质、生长调节剂含量、穴盘规格、插穗留叶量、插穗木质化程度对茶树穴盘育苗成活率、新梢长度、茎粗、着叶数的影响。结果表明,在珍珠岩与草炭2∶35混合基质中生长的茶苗成活率、新梢长度、茎粗、着叶数均较高,且成活率、新梢长度均显著高于其他处理。使用ABT1号生长调节剂对插穗进行0.5 h慢浸处理能提高茶树穴盘育苗成活率、茎粗,综合比较,以100 mg/kg处理效果较好。穴盘规格对茶苗新梢长度、茎粗、着叶数影响不大,但对每平方米成活茶苗数影响较大,128穴规格穴盘每平方米成活茶苗数显著高于其他处理。插穗留叶量对茶苗扦插成活率、茎粗、着叶数影响不大,对茶苗新梢长度影响较大,以保留全叶或1/2叶处理效果较好。不同插穗木质化程度对新梢长度影响不大,结合对成活率、茶苗茎粗、着叶数的影响效果,以绿梗或半木质化处理效果较好。

Quantitative Trait Loci Mapping for Leaf Length and Leaf Width in Rice cv.IR64 Derived Lines

The present study was conducted to identify quantitative trait loci （QTLs） for leaf size traits in IR64 introgression lines （INLs）. For this purpose, selected F2 populations derived from crosses between recurrent parent IR64 and its derived INLs, unique for leaf length and leaf width, were used to confirm QTLs. A total of eight QTLs, mapped on three chromosomes, were identified for the four leaf size traits in six F2 populations. A QTL for leaf length, qLLnpt-1, in HKL69 was identified around simple sequence repeat （SSR） marker RM3709 on chromosome 1. Two QTLs for flag leaf length, qFLLnpt-2 and qFLLnpt-4, in HFG39 were indentified on chromosomes 2 and 4, respectively. For flag leaf width, a QTL, qFLWnpt-4, in HFG39 was identified around RM17483 on chromosome 4. While another QTL for flag leaf width, qFLWnpt-1, in HFG27 was identified around RM3252 on chromosome 1. A QTL for leaf width, qLWnpt-2, in HKL75 was identified around RM7451 on chromosome 2. For leaf width, two QTLs, qLWnpt-4a, qLWnpt-4b, in HKL48 and HKL99 were identified around RM7208 and RM6909, respectively on chromosome 4. Results from this study suggest the possibilities to use marker-assisted selection and pyramiding these QTLs to improve rice water productivity.

枫香叶片变色期全长转录组测序及分析

枫香因其树形优美,入秋后叶色红艳或橙黄,极具观赏价值,是优良的景观生态树种。为了解枫香叶片变色及其次级代谢过程的遗传基础,该文以枫香5个叶片变色期叶片混合样品为材料,利用单分子实时测序技术(PacBio平台)对其进行全长转录组测序。结果表明:(1)全长转录组测序共获得41.04 Gb的高质量数据,从中鉴定出全长非嵌合序列563 180条,通过聚类和去冗余,获得27 269条高质量全长转录本。在27 269条全长转录本中预测到2 035条长链非编码RNA(lncRNA),并检测出14 892个简单重复序列(SSR)位点和1 856个转录因子。(2)基因注释结果表明,NR、GO、COG、KEGG等8个数据库共注释了24 857条转录本,KEGG数据库共获得了124个条代谢途径,主要有核糖体、碳代谢、氨基酸生物合成等,在类黄酮和叶绿素代谢途径中分别有49和71个转录本参与。上述结果初步揭示了枫香叶片变色期转录组信息以及功能特性,为后续研究枫香叶片变色分子机制、色素代谢合成途径和调控、相关功能基因克隆以及叶色改良提供基础数据。

水稻和陆稻分化相关性状的QTL分析及水旱不同栽培条件下连续选择的影响

本研究以来自云南的地方品种Ch5-10和Ch6-11为亲本,后代用SSD方法而得到的RIL9群体为试验材料,对水、陆稻差异性状(始穗期、剑叶宽、株高等)进行了考察,并利用SSR分子标记构建遗传连锁图谱,进行了各性状的QTL定位;在自然和人工选择的过程中,栽培稻无论是形态上还是基因组上,都发生多种多样的变化。利用F 2群体(父、母本和前述的SSD群体相同)采用Bulk混合选择的方法,在F 4代开始进行水、旱田两种条件下种植,以模拟水陆稻的分化条件,经过5代的种植后繁殖成株系,分别得到CA、CB两个群体。对这两个群体的水陆稻差异性状(始穗期、最高分蘖数、有效分蘖数、剑叶宽、株高等)进行了考察。结果表明,利用SSD方法而得到的RIL9群体对始穗期、剑叶宽、株高等3个性状进行QTL分析,两年共检测到19个QTL,分别位于1,2,3,7,8,9,11号染色体上。其中株高qPH-1效应最大,贡献率为22%(2009年安徽),16%(2009年北京),16%(2010年北京),表现为来自亲本Ch5-10的等位基因增加株高;利用Bulk方法而得到的CA群体(经过水田筛选5代、289个株系)和CB群体(经过旱田筛选5代、332个株系),考察其最高分蘖数、有效分蘖数、始穗期、株高、剑叶宽等5个性状。2009年安徽和北京两地试验发现:两群体间除安徽始穗期和北京剑叶宽差异不显著外,其他性状差异均达到极显著水平。根据氯酸钾抗性和低温发芽力的QTL定位结果,选择qSLtr-2、qSLratio-2、qRL28-2-1和qRL28-4附近的标记RM166、RM5472、RI05751和RM5979,及未定位到QTL的标记RM259对CA群体和CB群体进行基因型分析,两群体间t测验结果表明,RM5472、RI05751和RM5979差异均达到极显著水平,RM259和RM166差异不显著。说明在人工模拟水、陆稻选择的条件下这2个群体有了明显的分化。

烤烟新品系LY1306烘烤前后叶片变化和失水率研究

为研究烤烟新品系LY1306烘烤前后叶片变化情况,以秦烟96为对照,采用智能烤箱,分3次取下、中、上各部位烟叶,挂牌标记,烘烤前后分别测量叶长、叶宽和单叶质量,计算叶片失水率。结果表明,烘烤后,LY1306上、中、下部叶长分别减少10.93%、12.60%、11.51%,叶宽分别减少20.58%、24.56%、21.34%,叶长和叶宽失水率均小于秦烟96;2个品种(系)叶片干鲜比均表现为上部>中部>下部,LY1306上、中、下部叶片干鲜比均大于秦烟96。

烟草叶宽性状主效QTL定位及育种评价

为研究烟草叶宽性状调控的遗传规律,定位其主效QTL位点,利用烟草SNP芯片对构建的重组自交系(Recombinant Inbred Lines, RILs)群体(小黄金1025×Beinhart1000-1)进行基因分型,并使用IciMapping 4.2软件的ICIM-ADD方法在全基因组范围内定位到6个与叶宽性状相关的QTL,分别位于2、4、9、13、17和20号连锁群上,可以解释2.9%~36.8%的表型遗传变异;其中qMLW20-1可解释36.8%的表型变异,为主效基因。以K326为轮回亲本、Samsun为主效基因qMLW20-1供体亲本构建染色体片段代换系评估烟草叶宽主效QTL的遗传效应,结果表明,导入qMLW20-1主效基因能显著提高烟叶叶宽,其中G3材料显著提高了烟叶钾含量,感官质量等其他重要性状与对照无显著性差异,未携带不良性状基因,具有较好的育种利用价值。研究结果为克隆叶宽性状主效基因和进行分子改良奠定了基础。