番茄EMS突变体库的构建及表型分析

以番茄品种"14637"种子为试材,采用0.8%的甲基磺酸乙酯(EMS)处理种子12 h,然后分别在叶、花、茎、果实、种子等方面对M1和M2世代群体单株进行表型变异观察,同时利用20对SSR引物对M2代典型变异株系进行分析鉴定,构建番茄突变体库,以期为获得番茄新种质资源提供参考依据。结果表明:M1代群体发生了一些变异,如植株矮化、叶色变异、花朵畸形、茎细弱、果实畸形等,但表型变异现象不明显;M2代番茄群落筛选共发现65种变异类型,189株变异植株,突变率为12.89%,其中获得的有益突变类型有8种;对M3代中13个典型变异植株进行基因组水平的变异检测,通过SSR引物分析,发现13种突变体均发生了DNA水平上的变异。该研究初步构建了含有189株M2代植株、65种表型变异的番茄突变体库。     

西瓜EMS诱导的突变体筛选及表型分析

以甲基磺酸乙酯(Ethyl methane sulfonate,EMS)为诱变剂，分别采用浸种法和滴苗法处理西瓜种质M08的种子和幼苗，对M₁和M₂代群体单株叶、花、茎、果实等主要农艺性状进行观察、拍照、记录。在浸种法获得的749株M₁代单株中共发现叶片黄化、叶片畸形、雄花簇生、瓜胎形状变异等15种突变类型，总突变率达到20.56%；通过滴苗法共成活689株M₁代单株，包含10种变异类型，总变异率为19.30%。M₂代种子库共收获443份材料，随机选取其中的132个家系进行表型观测，共得到叶片黄化、子叶连结、叶片畸形、叶缘内卷、茎并生、果皮条带变异、植株生长发育迟缓等13种变异类型，总突变率为5.21%。对叶色黄化转绿突变体M₁-5家系的M₂代群体单株进行表型观测及光合特性分析得出，在转绿前，光合色素含量较低，叶片呈黄色；在转绿后，光合色素含量大幅度提高，叶色由黄转绿，但仍低于正常M08叶片，随着光合色素的累积，黄化转绿突变体的光合能...     

西瓜高代回交株系基因型分析(摘要)

西瓜品种资源遗传基础狭窄,在一定程度上对培育优质西瓜品种造成了困难。而野生西瓜具有许多优良的农艺性状,挖掘利用野生西瓜种质资源的有益基因,是西瓜品种改良的重要途径。以野生西瓜材料A69为供体亲本,栽培西瓜材料203Z为轮回亲本,通过连续回交,获得超过100个BC4株系。在BC4株系中发现了大量的果实性状变异,如不同瓤色、酸味、苦味、硬果皮、硬果肉、低糖等。选择其中的部分变异株系进行SSR标记,通过GGT遗传分析软件进行基因型分析。结果表明,选用的178对SSR引物在两个亲本材料之间具有多态性的引物有99对,多态率为55.6%,且多为共显性标记,说明两亲本材料遗传差异较大。以其中1株果肉硬度变异株系为例,发现在西瓜的第1、2、6、8、10、11染色体上存在7条不同长度的外源野生片段,且多为杂合片段,片段总长度为59.9 c M,平均片段长度为8.56 c M,最长片段为17.55 c M,最短片段为5.6 c M,背景恢复率为92.3%。同时对9个果肉硬度变异株系的基因型进行比较,发现有6个以上的不同单株在6条染色体上均存在外源野生片段,可以推测其中的一个或多个外源野生片段存在着控制果肉硬度大小的基因。     

引进豌豆种质资源遗传多样性分析

以引进的34份豌豆种质资源为试材,采用19个表型性状对其变异性、多样性和主成分分析进行了研究,结合SSR分子标记对其开展遗传多样性分析,以期加速豌豆种子资源研究进程。结果表明:19个性状在不同材料之间存在显著差异,平均变异系数为45.05%,平均遗传多样性指数为0.95;前7个成分占表达信息量的74.807%,其中第1主成分占表达信息量的18.350%,且第1主成分在脐色、粒色、叶面积、茎粗和花色等性状呈现较高的载荷量;表型性状分析将34份材料分成8类;分子标记研究结果显示,118对SSR引物共筛选出25对具有稳定多态性条带,共检测115个差异位点,每对引物平均4.6个,有效等位变异数为1.6944,有效等位变异所占比重为40.17%,Shannon信息指数为0.5941。运用NTSYS软件进行聚类分析,34份材料遗传相似系数(GS)为0.461~0.860,平均0.661,SSR标记分析引进的34份材料也被分为8类,2种分类方法呈现显著正相关(R=0.9013,P=0.1011>0.050)。该研究利用SSR分子标记从分子水平上揭示豌豆种质资源遗传背景和亲缘关系,可为今后豌豆资源的利用提供重要参考依据。     

菜薹品质性状与SSR标记的关联分析

为挖掘与菜薹品质性状相关的分子标记,选用具有多态性的84个SSR标记分析了81份菜薹种质材料的遗传多样性,并采用TASSEL3.0软件中混合线性模型(MLM)对菜薹群体材料的单株质量、叶绿素含量、维生素C含量、可溶性总糖含量、可溶性蛋白含量和硝酸盐含量等6个品质性状进行关联分析。结果显示,84个SSR标记在81份菜薹种质材料中共检测出310个等位位点,引物多态信息量(PIC)在0.1878～0.9902,平均值为0.6119;81份菜薹种质材料的遗传相似系数(GS)在0.4742～0.8958,平均值为0.6294;在GS值为0.596水平上,81份菜薹种质可聚为4个类群。关联分析显示,10个等位位点与菜薹4个品质性状显著相关(P 0.01),对表型变异的贡献率为8.59%～11.50%,其中5个等位位点表现为增效表型效应,其余5个等位位点为减效表型效应。基于等位位点的分析结果,鉴定出典型的载体材料11份,分别携带有4～8个优异等位位点。本研究发掘的与菜薹品质性状相关的优异等位位点及载体材料,可为高品质菜薹的分子标记辅助育种提供参考。     

西瓜种质资源的遗传多样性分析

对88份来源不同的西瓜种质资源,采用37个表型性状和22对SSR分子标记进行遗传多样性分析。结果表明:表型性状变异主要体现在果实形状、品质和叶片等性状上,第1、第2、第3主成分的方差贡献率分别为13.6%、11.8%和9.0%,前3个主成分的累计为34.4%,依据表型性状进行聚类分析,在欧氏距离15.0时,可将材料分成2类,在欧氏距离13.5时,可将材料分为3类;SSR分子标记共扩增出的55个多态性位点,平均多态性信息含量为0.41,利用UPGMA法进行聚类分析,88份西瓜种质可以被分为4个组。第1、第2、第3主坐标的方差贡献率分别为22.8%、10.8%和9.1%,前3个主坐标累计为42.7%。     

EMS诱变的‘里格尔87-5’番茄M_2群体突变体表型及其抗坏血酸研究

构建番茄突变体库对于丰富遗传变异、发掘基因资源具有重要意义。利用1%的甲基磺酸乙酯(EMS)处理‘里格尔87-5’加工番茄种子12 h,对M_2代材料进行农艺学性状与生物学性状鉴定,对部分M_3代材料进行遗传稳定性验证。在M_2代筛出典型突变体,包括早衰、矮化、圆果、低抗坏血酸、黑斑、绿茎、簇生等突变单株。对240个M_2代家系中共1 023个单株全生育期田间表型进行观察鉴定和果实品质测定,共发现90个变异单株,其中13个突变单株同时出现两个或两个以上变异性状,共50个变异性状,总的单株变异频率(突变株/总株数)为8.80%。叶、茎、花、果实和植株发生的变异株数分别为27、7、17、56和21,性状变异频率分别为2.64%、0.68%、1.66%、5.47%和2.05%。其中矮化突变体分子鉴定表明,curl-3基因外显子中C变成T,氨基酸由L变成F,喷施油菜素内酯不能恢复其正常生长,表明curl-3突变导致油菜素内酯信号传导受阻。curl-3突变体叶片与果实中抗坏血酸含量下降,并伴随着叶片中氧化态与还原态抗坏血酸比值增加,这可能与抗坏血酸氧化酶基因AO表达量和AO酶活性增强有关。     

蚕豆种质资源种子表型性状精准评价

为深入了解蚕豆种质资源种子表型性状特征及相关性,以防虫网隔离纯化1代的554份国内外蚕豆种质资源为试材,利用相关分析、主成分分析、聚类分析等方法,对采用数码考种仪获得的种子表型性状进行了综合分析。结果表明:供试蚕豆种质资源种子表型变异范围广,遗传多样性丰富,以百粒重的变异最大;百粒重、种子投影面积、周长、粒长、粒宽和直径这6个表型性状之间具有较高的相关性,相关系数均大于0.80且达到了极显著水平;对8个数量性状进行主成分分析,前3个主成分的贡献率分别为74.60%、23.09%和1.70%,累计贡献率达到99.39%,几乎覆盖参试种子数量性状的全部信息,上述6个表型性状的变异对第1主成分贡献较大,均为籽粒大小性状;聚类分析将所有参试材料聚为3类,与播期和地理来源有一定相关性。基于种子表型性状的综合分析,筛选出11份具有近圆形种子、适宜全程机械化种植和8份具有高产潜力的优异蚕豆资源。     

野生荠菜的株型研究以及品性分析

通过对野生的5个中选的荠菜单株进行留种,将这些种子按株系进行人工栽培,观察并统计其生物学特性、生产特性等株型特点,对其子一代进行比较。得出株系内有一定的分离,但差异不是很大,株系间差异明显。其中2个株系适宜栽培。     

莲子产量相关性状的QTL定位

以中国长江流域圆柱形莲子资源‘中间湖野莲’为母本，泰国圆球形莲子资源‘清迈野莲’为父本，构建了含86个单株的F2遗传群体。2017和2018年对亲本及群体黑子期莲子长、莲子宽、单粒质量、开花数、心皮数、饱粒数等6个莲子产量相关性状进行了表型鉴定，利用197个SSR标记对亲本及F2单株进行基因分型，结合表型和基因型数据对相关性状进行了QTL定位和分析。结果表明：莲子产量相关性状在F2群体中均呈近正态连续分布，表明均为多基因控制的数量性状。6个莲子产量相关性状共检测到28个QTL位点，分布在7条连锁群上，LOD值变幅为2.55 ~ 12.34，可解释5.5% ~ 27.4%表型变异率。贡献率 ≥ 10的QTL位点有25个，占QTL总数的89.29%。黑子期莲子长（bsl1），莲子宽（bsw6）、开花数（fn4.1，fn5）可在两年被稳定检测到，贡献率变幅为7.33% ~ 17.6%。     

Greenhouse tomato limited cluster production systems: crop management practices affect yield

Limited-cluster production systems may be a useful strategy to increase crop production and profitability for the greenhouse tomato (Lycopersicon esculentum Mill). In this study, using an ebb-and-flood hydroponics system, we modified plant architecture and spacing and determined the effects on fruit yield and harvest index at two light levels. Single-cluster plants pruned to allow two leaves above the cluster had 25% higher fruit yields than did plants pruned directly above the cluster; this was due to an increase in fruit weight, not fruit number. Both fruit yield and harvest index were greater for all single-cluster plants at the higher light level because of increases in both fruit weight and fruit number. Fruit yield for two-cluster plants was 30% to 40% higher than for single-cluster plants, and there was little difference in the dates or length of the harvest period. Fruit yield for three-cluster plants was not significantly different from that of two-cluster plants; moreover, the harvest period was delayed by 5 days. Plant density (5.5, 7.4, 9.2 plants/m2) affected fruit yield/plant, but not fruit yield/unit area. Given the higher costs for materials and labor associated with higher plant densities, a two-cluster crop at 5.5 plants/m2 with two leaves above the cluster was the best of the production system strategies tested.     

Regeneration and characterization of Swertia chirata Buch.-Ham. ex Wall. plants from immature seed cultures

First generation immature seeds (R₁) were collected from a field transferred micropropagated plant and seeds were induced to develop organogenic calli in Swertia chirata, a traditional revenue earning medicinal plant. Half strength MS medium with different growth regulators namely, BA, Kn (2.22–4.44 μM), NAA (2.69–5.37 μM), and 2.26 μM 2,4-D were used to induce callus and organogenesis. Isolated shoots produced roots either in the same medium or in presence of NAA (2.69–10.74 μM) or IBA (2.46–9.8 μM). Fully developed plantlets were successfully transplanted to soil and the fertile seed bearing plants developed. Occasionally plants derived from more than 56 weeks old calli showed some morphological variations. Such variations in regenerated plants is not reflected in their chromosomal constitution, with normal 2n = 26 chromosomes. Likewise, no variation was observed in DNA fingerprinting patterns among the short-term raised culture regenerants, which were morphologically similar to that of the donor plant illustrating their genetical uniformity and clonal fidelity. On the contrary, variation in DNA fingerprinting patterns was observed in long-term culture raised plants.     

太空诱变对乐都长辣椒后代农艺性状的影响

对＂实践八号＂返回式卫星搭载乐都长辣椒种子及其后代的农艺性状进行了调查和分析,结果表明,乐都长辣椒种子经太空诱变处理后,当代（SP1）与对照在生育期、出苗率、成苗率、植物学性状、果实性状及产量指标上均无显著性差异,但在SP2代中,生育期提前,出苗率和成苗率提高,其各项农艺性状均表现出不同程度的差异,从后代中有可能选择出优良的变异单株或群体。     

The effect of the time of taking side shoots on the regulation of fruit size in glasshouse-grown tomato crops

Summary

Young tomato plants were transferred to heated glasshouse compartments on 9 December at a density of 2.04 plants m-2 and grown as a conventional long-season tomato crop. Beginning in either the third, fifth, seventh or ninth week of the year, every other plant was allowed to retain one side shoot so as to increase the effective plant density to 3.06 plants m-2. Control crops were grown throughout at both the initial and the final densities. Two different patterns of taking the side shoots were tested in two sub-treatments: taking the required number of side shoots in four tranches over a period of six weeks was neither significantly better nor worse than taking them in two equal tranches, four weeks apart. The main effect of adding side shoots was to increase the number of fruit harvested per m-2, as compared with a control crop grown throughout at the initial density of 2.04 plants m-2. However, these additional fruit were not harvested until at least 80.d after the first side shoots had been allowed to grow. When side shoots were taken as early as week 3, a high proportion of the marketable fruit were in the preferred size (viz.47to57.mm in diameter, 50 to 90.g in weight, UK grade D) in all harvest periods. Thus, the additional side shoots enabled the crop to bear extra fruit and when the side shoots were taken early, the production of additional fruit coincided with the time when both the quantity of solar radiation incident per day and the concomitant assimilate production were increasing rapidly. Consequently, the supply of assimilates and the numbers of fruit available per m-2 were better matched for the purpose of continually producing fruit of one size. However, the presence of side shoots tended to reduce the number of marketable fruit carried on each truss. The addition of side shoots increased leaf area index and also significantly increased total fruit yield. The increased area of foliage served to shade more fruit from the heating effects of incident solar radiation and a smaller proportion of marketable fruit was downgraded to Class II in all side-shoot treatments. In general, the means of the four successive side-shoot treatments provided a graded series between those of the fixed low-density and the fixed high-density control treatments.     

Responses of field grown tomato plants to arbuscular mycorrhizal fungal colonization under varying intensities of drought stress

The effects of root colonization by the arbuscular mycorrhizal (AM) fungus Glomus intraradices Schenck and Smith on growth, flower and fruit production, and fruit quality were studied in field-grown tomato plants exposed to varying intensities of drought stress. Inoculated (M+) and non-inoculated (M−) tomato seedlings were exposed to varying intensities of drought stress by adjusting irrigation intervals. Mycorrhizal plants had significantly higher uptake of N and P in both roots and shoots regardless of intensities of drought stress. AM inoculation also significantly increased shoot dry matter and the number of flowers and fruits. The fruit yields of M+ plants under severe, moderate, mild drought-stressed conditions were higher than M− plants by 24.7%, 23.1%, 16.2% and 12.3%, respectively. Furthermore, M+ plants produced tomato fruits that contain significantly higher quantities of ascorbic acid and total soluble solids (TSS) than M− plants. Mycorrhizal effects increased with increasing intensity of drought. The overall results suggest that mycorrhizal colonization affects host plant nutritional status, water stratus and growth under field conditions and thereby alters reproductive behaviour, fruit production and quality of fruits under both well-watered and drought-stressed conditions.     

朝天椒种质材料主要园艺性状差异性分析

对156个朝天椒种质材料的形态特征、主要园艺性状等方面的差异性进行研究分析,结果表明：朝天椒种质材料形态差异主要表现在株型、果形、果色、果实着生特征、叶形、叶色、花型、花色、茎杆色等方面;主要园艺性状的差异主要表现在全生育期、苗期、花果期,株高、株幅、茎粗、始花节高、侧枝数、叶长、叶宽、果长、果宽、果肉厚、单株挂果数、单果重、单果种子数、种子千粒重等性状,其变异系数分别为4．59％、6．32％、10．25％、15．31％、19．31％、13．44％、13．66％、55．52％、7．36％、15．01％、47．90％、37．93％、30．77％、61．34％、62．32％、34．11％、1．32％。．     

氮离子注入黄瓜诱变遗传育种研究

研究了不同氮离子注入黄瓜干种子次数后诱变效应的变化。结果表明:经过氮离子注入处理后的黄瓜均出现了较明显的突变,并且经过2次氮离子注入诱变处理的突变率高于只经过一次氮离子注入诱变处理7.9个百分点,2个处理中黄瓜M1代出现多种类型明显变异植株,M2代在瓜形突变上出现较大分离,M3代密刺瘤变异和瓜条变短变异遗传稳定,最高遗传率达到99.3%,并且得到了黄瓜商品性状改变优良的突变系。     

苦瓜种子EMS 诱变条件分析

以江门大顶苦瓜自交系干种子为材料，设置EMS 溶液不同浓度（0、0.3%、0.6%、0.9%、1.2%、1.5%）和不同诱变时间 （2、4、6 h）处理组合，通过统计苦瓜种子发芽势和发芽率指标以及M₀ 植株表型观察来确定苦瓜种子EMS 诱变的适宜条件。 结果表明，EMS 溶液浓度、诱变时间以及两者的互作均对苦瓜种子发芽势和发芽率具有显著的影响；根据半致死条件原则， 初步认为清水浸种8 h，然后利用1.5% 或1.2% EMS 溶液处理2 h 是苦瓜种子EMS 诱变的适宜条件；将1.2% 或1.5% EMS 溶 液处理2 h 所获得的共129 株M₀ 苦瓜幼苗进行田间定植和表型观察，发现苦瓜植株表型突变频率分别为5.12% 和7.85%，且 表型变异多发生于叶片和果实，表明所筛选的诱变条件可以用于苦瓜种子EMS 诱变研究。试验结果为下一步利用EMS 诱变 技术开展苦瓜突变体库构建以及创制苦瓜新材料奠定了基础。     

不同施肥水平对日光温室基质袋培番茄营养及栽培效果的影响

为了明确日光温室基质袋式栽培番茄的施肥方案,以圣罗菲为试材,研究了4种施肥水平〔CK:经验型施肥量,F1:标准施肥量(参考以色列番茄营养液配方和施肥方案制定),F2:低于标准施肥量20%,F3:高于标准施肥量20%〕对基质袋培番茄的生长、产量、品质及养分利用的影响。结果表明:F2处理的番茄植株长势较好、最粗壮,植株生物量和单株果实产量均显著高于其他处理,N肥和K肥的利用率亦高于其他处理,果实品质与其他施肥处理差异不显著,可以作为日光温室番茄基质袋培的推荐施肥方案。