甘薯胡萝卜素含量、干率聚合育种的一个特例

2005年采用高胡萝卜素、低干双亲的特殊组合‘浙薯81’ב浙薯255’创制出甘薯优异高干红肉品种‘浙薯13’。为了探索甘薯胡萝卜素含量、干率聚合育种新方法,2016年对这一双亲的正反交组合F1胡萝素含量、干率进行了测定和遗传分离规律分析。结果表明,正反交组合的胡萝卜素含量遗传主要受非加性效应控制,组合传递力分别为45.32%和49.73%。干率不仅存在加性效应,而且呈明显的超亲遗传,正反交组合的超亲优势分别达到15.12%和12.75%,超高亲率约70%,呈现相当于高干×低干的遗传分离,中、高干类型比例高达60%左右,其中高干类型比例约28%。杂交后代含有干率≥25%、胡萝卜素含量≥3 mg/100 g FW的株系占26.10%,含有干率≥25%、胡萝卜素含量≥10 mg/100 g FW的株系占9.78%。干率是甘薯食味的主要影响因子。因此,‘浙薯81’与‘浙薯255’杂交可以高效地聚合胡萝卜素含量和干率,大幅度提高优质食用高胡萝卜素育种的筛选效率。     

Diallel analysis of sweetpotatoes for resistance to sweetpotato virus disease

Sweetpotato virus disease (SPVD) is due to the dual infection and synergistic interaction of Sweetpotato feathery mottle potyvirus (SPFMV) and Sweetpotato chlorotic stunt crinivirus(SPCSV), and causes up to 98% yield loss in sweetpotato in East Africa. This study was conducted to determine the inheritance of resistance to SPVD in sweetpotato and to estimate the nature of genetic variance. Ten parental clones varying in reaction to SPVD were crossed in a half diallel mating design to generate 45 full-sib families. The families were graft-inoculated with SPCSV and SPFMV to induce SPVD and evaluated for resistance in a randomized complete block design at two sites in Namulonge, Uganda during 1998–2000. In serological assays for SPFMV and SPCSV,resistance to symptom development and recovery from initial systemic SPVD symptoms, characterised resistant genotypes. Genetic component analysis showed significant effects for both general combining ability (GCA) and specific combining ability (SCA) for resistance to SPVD. GCA to SCA variance component ratios were large (0.51–0.87), hence GCA effects were more important than SCA effects. Resistant parents exhibited high GCA indicating that additive gene effects were predominant in the inheritance of resistance to SPVD and recovery. Narrow-sense heritability (31–41%) and broad-sense heritability (73–98%) were moderate to high, indicating that rapid genetic gains for SPVD resistance could be accomplished by mass selection breeding techniques. Two genotypes, New Kawogo and Sowola, had high negative GCA effects and had several families in specific crosses,which exhibited rapid recovery from SPVD,and are promising parents for enhancement of SPVD resistance and recovery. This revised version was published online in August 2006 with corrections to the Cover Date.     

钾肥不同施用期对食用甘薯产量和品质的影响

为了探明适宜的钾肥施用量与施肥时期在提高甘薯产量和品质的同时,实现钾肥的高效利用和优化管理。以优质食用型甘薯徐薯32为试验材料,研究3个钾肥用量（0,150,300 kg／hm2）和3个施钾时期（生长早期即栽插后2周内、封垄期和块根膨大初期）处理对甘薯产量及营养成分的影响。结果表明：生长早期施用钾肥300 kg／hm2时,块根鲜薯和薯干产量获得最高值,分别为36495．0,12175．5 kg／hm2。钾肥不同施用期和施用水平对所测甘薯品质性状影响较大,甘薯生长早期追施钾肥有利于淀粉、麦芽糖和蔗糖的积累;低钾处理有利于淀粉及糖类物质的积累,而高钾处理则有利于蛋白质的积累。     

30个中国甘薯主栽品种的RAPD指纹图谱构建及遗传变异分析

研究以中国30个甘薯主栽品种为材料,对甘薯RAPD指纹图谱的构建进行了探讨。从102个RAPD引物中筛选出26个多态性丰富的引物用于PCR扩增,共扩增出255条多态性条带,平均每个引物扩增的多态性带数为9.8条。其中S32和S39多态性最高,仅用其中1个引物即能将这30个甘薯品种完全区分开,且由此构建的指纹图谱出现的概率很小,分别为4.77×10^-7（1/221）和1.91×10^-6（1/219）。结果进一步表明,这30个甘薯品种的遗传距离变异幅度较大,为0.0390～0.4306,平均遗传距离为0.3086。RAPD聚类分析表明,地域分布相近的甘薯品种和具有同一亲本的甘薯品种聚在一起,与这些甘薯品种的系谱图一致。     

The effects of ethylene, 1-MCP and AVG on sprouting in sweetpotato roots

Exogenous ethylene is commonly used as a commercial sprouting inhibitor of potato tubers. The role of ethylene in the control of sprouting of sweetpotato roots, however, is not known. The aim of this study was to investigate the role of ethylene in control of sprouting in sweetpotato roots by observing the effect of an ethylene synthesis inhibitor, aminoethoxyvinylglycine (AVG), and the ethylene antagonist, 1-methylcyclopropene (1-MCP), in the presence and absence of exogenous ethylene on root sprouting and associated sugar accumulation. Continuous exposure to 10 μl L⁻¹ ethylene, 24 h exposure to 625 nl L⁻¹ 1-MCP or dipping in 100 μl L⁻¹ AVG all inhibited sprout growth in sweetpotato roots of two varieties over 4 weeks of storage at 25 °C. The observations that both ethylene on its own and 1-MCP, which inhibits ethylene action, inhibit sprout growth indicate that while continuous exposure to exogenous ethylene leads to sprout growth inhibition, ethylene is also required for sprouting. In potato tubers ethylene is required to break dormancy, while continuous exposure inhibits sprout growth.Monosaccharide concentrations in ethylene, 1-MCP or AVG treated roots were lower than in untreated roots, and for ethylene treated roots this was associated with higher respiration rates. This is consistent with the activation of some additional process by ethylene which uses energy through sugar metabolism. 1-MCP and AVG both inhibited this increase in respiration rate and counteracted the decrease in monosaccharide concentrations. 1-MCP presumably counteracts the ethylene stimulation of this process, while the effect of AVG is attributed to its possible inhibitory effects on protein synthesis.     

腐植酸提高食用型甘薯块根可溶性糖含量的生理基础

选用典型的食用型甘薯品种北京553,设置施用腐植酸和对照处理,于2008-2009年2个生长季在山东农业大学农学试验站进行试验。在甘薯块根膨大过程中定期取样,测定块根可溶性糖和淀粉含量及相关酶活性、功能叶蔗糖含量及相关酶活性变化。结果表明, 与对照比较,施用腐植酸显著提高了功能叶磷酸蔗糖合酶活性和蔗糖含量,生育期内平均增幅分别为30.90%和9.48%,显著降低了块根蔗糖合酶活性,平均降幅为11.04%,促进了蔗糖、果聚糖等在块根中的积累;同时,施用腐植酸还显著提高了块根中淀粉酶活性,α-淀粉酶和β-淀粉酶平均增幅分别为11.33%、15.70%,促进了后期葡萄糖、果糖等在块根中的积累。在甘薯收获期,块根可溶性总糖含量提高了15.49%、淀粉含量降低了3.56%。总之,施用腐植酸能够增加块根中蔗糖的供应量、抑制可溶性糖向淀粉转化、促进淀粉水解,这些是提高块根可溶性总糖含量的生理基础。     

Genetic diversity in sweetpotato [Ipomoea batatas (L.) Lam.] in relationship to geographic sources as assessed with RAPD markers

Available evidence shows that sweetpotato originated from either Central or South American lowlands with subsequent dispersal to North America, Europe, Africa, Asia and the pacific islands. A total of 71 polymorphic RAPD molecular markers were used to assess the genetic relationships amongst 74 sweetpotato varieties originating from a total of 23 sweetpotato producing countries within six geographical regions, namely, South America, Central America/Caribbean, United States of America (USA), East Africa, Asia and Oceania. An Analysis of Molecular Variance (AMOVA) indicated that 93.4% of the total variance was due to the differences between genotypes within regions. The difference between regions was significant (P < 0.001) but only contributed 6.6% to the variance. Genetic distance (PhiST) calculated with AMOVA and multidimensional scaling (MDS) revealed that the South American and the Central American/Caribbean genotypes formed two separate clusters. East African varieties, which have unique characteristics from other traditional varieties, were distinct from other traditional varieties from South America and Oceania. These results support the reported hypothesis of the origin and dispersal of the sweetpotato and indicate that the primary centre of diversity probably has two distinct genepools. It is proposed that the dispersal of the sweetpotato from its origin may have mainly involved varieties from Central America/Caribbean as opposed to varieties from South America. There is an indication that new genepools may be evolving in Africa and Asia due to hybridisation and adaptation to the local environments.     

福建省露地及设施蔬菜烟粉虱越冬种群密度及耐寒性研究

2017年1月9—12日和2月21—24日,在南平建瓯、三明将乐、三明三元、福州闽侯、龙岩新罗以及漳州龙海等6个地区,调查了大棚和露地烟粉虱越冬寄主及种群密度,以期明确福建省露地及设施蔬菜烟粉虱越冬规律,为烟粉虱的综合治理提供理论依据。共记录烟粉虱越冬寄主6科16种,主要包括栽培蔬菜花椰菜、番茄、茄子以及阔叶类杂草龙葵、小飞蓬、辣子草和胜红蓟。在露地花椰菜上,烟粉虱越冬虫口密度1月份显著高于2月份;花椰菜采后残株上的越冬虫口密度显著高于莲座期和花球形成期。在温室大棚中,休耕大棚中越冬虫口密度显著高于生产大棚。无论是蔬菜还是杂草,温室大棚中的越冬虫口密度显著高于露地。烟粉虱各虫态均可在各地温室大棚和漳州露地越冬,而在南平和三明等温度较低的地区以卵和伪蛹在露地越冬。在蔬菜上发现越冬烟粉虱有MEAM1隐种和MED隐种,温室大棚中两隐种数量分别为57只和111只,温室大棚可能有助于MED隐种定殖。室内耐寒性测定证实卵和高龄若虫比低龄若虫以及成虫更耐寒,烟粉虱在花椰菜、龙葵和辣子草上的世代存活率分别为83.7%、79.3%和81.6%,世代发育历期分别为18.9 d、16.7 d和18.8 d,龙葵和辣子草是烟粉虱适宜的越冬杂草寄主。综上,烟粉虱可在福建省露地越冬,温室大棚加重了烟粉虱的发生为害。     

In Vitro Selection and Identification of Drought-Tolerant Mutants in Sweetpotato

In vitro selection of drought-tolerant mutants in sweetpotato cv. Lizixiang was studied by using PEG6000 as selection stress. Embryogenic suspension cultures were cultured in MS medium containing 0-35% PEG6000 and 2 mg L-1 2, 4-dichlorophenoxyacetic acid (2, 4-D). The results indicated that 30%PEG6000 can be used for the optimal selection stress of drought-tolerance. Embryogenic suspension cultures irradiated with 80 Gy gamma-ray were cultured in MS medium containing 30 % PEG6000 and 2 mg L-1 2,4-D and 20 drought-tolerant cell aggregates were obtained. These cell aggregates were transferred to solid MS medium supplemented with 2 mg L-1 2,4-D and formed embryogenic callus with somatic embryos. The embryogenic callus with somatic embryos was further transferred to MS medium supplemented with 1 mg L-1 abscisic acid (ABA), resulting in the germination of somatic embryos. In this study a total of 18 regenerated plants were obtained. The regenerated plants were transplanted in a greenhouse and 11 lines were formed. The analysis on drought treatment of seedlings, water retaining capacity of leaves and coefficient of drought-tolerance showed that 3 lines had significant drought-tolerance in comparison with the control plants.     

水分胁迫下甘薯内源激素的变化与品种抗旱性的关系

 采用酶联吸附免疫法 (ELISA) ,测定了干旱条件下甘薯叶片内吲哚乙酸 (IAA)、赤霉素 (GA3 )、异戊烯基腺嘌呤 (iPA)、玉米素核苷 (ZR)和脱落酸 (ABA)等 5种内源激素的含量 ,并研究了这些内源激素与品种抗旱性的关系。结果表明 ,水分胁迫下甘薯各品种中IAA、GA3 、iPA及ZR含量均有所下降 ,ABA含量却显著增加 ,且品种抗旱性愈强 ,IAA、GA3 、iPA和ZR下降幅度愈大 ,ABA增加幅度愈小。它们的相对含量 (占对照 % )与品种抗旱性均呈极显著负相关 (r分别为 - 0 .90 70、- 0 .94 93、- 0 .95 0 9、- 0 .86 74和 - 0 .9117)。