2个百脉根品系种子萌发期的耐盐性评价

为探究2个百脉根（Lotus corniculatus L.）品系B1（来源于加拿大圭尔夫）和B2（引种于加拿大）种子萌发期的耐盐性,采用纸上发芽法,以蒸馏水为对照,采用不同浓度（0.3%,0.6%,0.9%,1.2%）NaCl溶液,通过测定发芽率、根长、苗长等7项指标,计算其盐害系数,利用方差分析、主成分分析以及隶属函数对其进行了综合评价。结果表明：随着盐浓度的增加两个百脉根品系的发芽指数呈现出先升高后下降的趋势,活力指数呈现先降低后升高再降低的趋势,其他指标的变化趋势均不一致。方差分析结果表明,当盐浓度为1.2%时,B2的发芽率、发芽势、发芽指数、苗长和幼苗干重均显著高于B1（P<0.05）。综合评价结果表明,种子萌发期耐盐性较强的是品系B2。     

白三叶耐酸铝种质资源筛选研究

以来源于俄罗斯的57份白三叶种质资源和9份国内外育成品种为试验材料,研究酸铝胁迫对白三叶种子萌发指标和根系指标的影响。研究结果表明,酸铝胁迫对白三叶种子萌发和幼苗生长均有不同程度的抑制作用。通过指标相关性分析和因子主成分分析,筛选出白三叶耐酸铝性评价指标为相对活力指数、相对发芽势和相对胚根平均直径。用加权隶属函数方法对66份白三叶材料萌发期的耐酸铝性进行综合评价,通过系统聚类筛选出耐酸铝性强的6份种质资源：‘海发’、‘ZXY06P-1927’、‘ZXY06P-1768’、‘ZXY06P-1879’、‘ZXY06P-2029’和‘ZXY06P-2659’。     

无芒隐子草和条叶车前种子萌发特性的研究

研究了无芒隐子草和条叶车前种子千粒质量大小和环境温度对其发芽率和幼苗生长的影响。结果表明,无芒隐子草和条叶车前种子的千粒质量分别为0.238g和1.770g。无芒隐子草种子萌发对环境温度适应性较强,能在10～50/20℃温度区间萌发,较高温度促进萌发;条叶车前种子萌发对环境温度适应性较弱,在10～30℃温度区间,较低温度促进其萌发。无芒隐子草和条叶车前种子的最佳萌发温度分别为35/20℃变温和20℃恒温,在此条件下的发芽率分别达94%和61%。     

Imbibition behavior and flooding tolerance of rapeseed seed (<Emphasis Type="Italic">Brassica napus</Emphasis> L.) with different testa color

In this study, the correlations among these characters were investigated in 18 rapeseed (Brassica napus L.) accessions with different seed coat color. The results indicated that seed water uptake and flooding tolerance were significantly correlated with seed color and melanin pigment content of testa. The red or black-seeded accessions had higher melanin content in testa, showed slower water uptake and lower leakage and higher flooding tolerance. The majority of yellow-seeded rapeseed accessions which had low melanin pigments content in testa showed a rapid water uptake and higher leakage than the red or black-seeded, which led to imbibition damage and lower flooding tolerance. The results suggest that the yellow-seeded cultivars experienced poor field emergence and more serious pre-harvest sprouting in raining weather than the dark-seeded cultivars. Some yellow-seeded accessions showed a slow imbibition behavior and relative high flooding tolerance, indicated these accessions can be used as a genetic resource to improve the flooding tolerance and reduce imbibition damage for the yellow-seeded B. napus L.     

野生大豆和不同栽培大豆品种在镉胁迫下种子萌发及幼苗生长的差异

为探讨野生大豆和不同栽培大豆品种在镉胁迫下种子萌发的差异,筛选优质的大豆耐镉资源,首先比较5种镉浓度(5,10,25,40 mg·L^-1)对野生大豆与栽培大豆的种子发芽率、发芽势、发芽指数、活力指数、根长及芽长等参数,筛选出对镉敏感的性状及适中的镉浓度处理;然后以此为基础比较野生大豆1503、超高产大豆(沈农9号和辽豆14)及普通栽培大豆(辽豆16和沈农20)耐镉性差异。结果表明:野生豆1503和栽培豆辽豆16种子的发芽率、发芽势及发芽指数在较高浓度(25或40 mg·L^-1)处理时明显下降,其它浓度处理与对照差异不明显或者高于对照,而活力指数、根长及芽长等指标在较低浓度(5或10 mg·L^-1)处理时就表现明显的被抑制效应,尤其对根长抑制更明显。活力指数、根长及芽长对镉胁迫更为敏感,可以作为鉴定耐镉材料及监测镉胁迫对植物的影响的重要指标。在5 mg·L^-1镉处理下,1503的活力指数、根长、芽长与对照差异不显著,10 mg·L^-1时显著下降,辽豆16在5 mg·L^-1时3种参数显著低于对照,因此镉浓度5 mg·L^-1的处理适中,可用来比较不同品种的耐镉性。在5 mg·L^-1镉处理下,按照3个敏感性状的平均值,筛选出耐镉性较强野生豆1503,镉性较弱的栽培豆沈农20,可用于耐镉育种及耐镉机制研究。     

水氮互作对百农207种子发芽特性及贮藏物质转运的影响

为了研究不同水氮处理下收获的百农207种子发芽特性和贮藏物质转运的差异,以百农207为材料,结合当地冬小麦灌溉施肥制度设置水氮两因素裂区试验,水分为主区,氮素为副区,设置W0(返青后不灌水)、W1(返青后灌拔节水)、W2(返青后灌拔节水和开花水)、W3(返青后灌拔节水、开花水和灌浆水)4个灌溉水平以及N0(不施氮)、N1(120kg·hm-2)、N2(180kg·hm-2)、N3(240kg·hm-2)4个施氮水平。在百农207收获后进行标准发芽实验,测定种子的发芽指数、活力指数、生长特性和贮藏物质转运等相关指标。结果表明,灌水和施氮对收获后的百农207种子活力指数、幼苗根冠比、贮藏物质转运率和转化效率的影响呈正向耦合效应。水分是决定收获后小麦种子活力指数、种子贮藏物质转运率和转化效率的主要因子;氮素是决定收获后种子发芽阶段根冠比的主要因子。高水肥处理(N3W3)的种子发芽指数和活力指数最高,水分和养分胁迫(N0W0和N1W0)下发芽阶段的根芽长比值较高。在一定施氮量范围内,增加灌水并不能促进收获种子在发芽阶段幼苗根冠比的增加。在W2和W3水平下,不同施氮处理的百农207种子贮藏物质转运率和贮藏物质转化效率均高于60%。种子发芽阶段幼苗生长相对最优的水氮处理为N2W2。这说明一定水分和氮素营养供应范围内降低氮肥用量,不会降低收获后百农207种子的贮藏物质转运率和转运效率,符合当前的减肥增效原则。     

NaCl胁迫下盐生草在不同重金属处理下的萌发特性分析

本研究首次以盐生草（Halogeton glomeratus）为材料,模拟盐胁迫（100 mmol·L^-1 NaCl）环境,探讨不同浓度重金属Cu²⁺,Zn²⁺,Ni²⁺,Cd²⁺,Pb²⁺处理对其萌发特性的影响。结果表明：随处理浓度的升高,发芽率和发芽势均表现为先升高后下降趋势,表明低浓度重金属离子可促进植物的萌发,幼苗鲜重、干重、株高均呈现逐渐下降趋势。测定离子含量得出,Cd²⁺和Pb²⁺离子含量随着胁迫加重呈先升高后下降的趋势,Cu²⁺,Zn²⁺和Ni²⁺离子含量逐渐增加。测定根系活力发现,Cu²⁺,Zn²⁺根系活力随浓度的升高呈先上升后下降趋势,Ni²⁺,Cd²⁺,Pb²⁺根系活力逐渐降低。综合聚类及主成分分析得出：盐生草耐Cu²⁺,Zn²⁺,Ni²⁺,Cd²⁺,Pb²⁺的临界浓度分别为：1.00 mmol·L^-1,10.00 mmol·L^-1,0.30 mmol·L^-1,0.20 mmol·L^-1和0.50 mmol·L^-1,在胁迫浓度达临界值时贡献率最大的指标分别为：萌发指标、干重、发芽势、干重和发芽势。     

燕麦种子萌发期抗旱能力的综合评价

为了研究不同燕麦材料的抗旱能力,以83份燕麦为试验对象,以200 g/L聚乙二醇(PEG-6000)进行胁迫处理,测定各燕麦品种的相对发芽势、相对发芽率、发芽指数、种子萌发率、发芽势和发芽率共6个形态指标,通过计算并绘制韦恩图,筛选出9份抗旱性较强的燕麦材料。进一步对9份燕麦萌发期的丙二醛(MDA)质量摩尔浓度、脯氨酸(Pro)质量分数、过氧化物酶(POD)活性及超氧化物歧化酶(SOD)活性进行测定。在主成分分析的基础上,利用加权隶属函数法构建燕麦萌发期抗旱性的综合评价体系,探究燕麦种子萌发的抗旱评价指标。通过两种指标同时检测和相互映证,建立萌发期燕麦抗旱综合评价体系,研究结果表明‘2010-48’和‘H44’为强抗旱品种;‘2010-5’和‘04-111’为中抗旱品种;‘ly05-2’‘05-22’‘06-31’‘2010-26’‘05-34’为弱抗旱品种。     

Occurrence of viable unreduced pollen in a <Emphasis Type="Italic">Begonia</Emphasis> collection

Polyploidy is widespread in plants and has played a major role in the evolution and diversification of the plant kingdom. Unreduced (2n) gametes are an interesting tool for polyploidisation and the creation of genetic variation in plant breeding. Especially in ornamentals, polyploidisation can broaden attractive features within a species. A Begonia collection was screened on the occurrence of 2n pollen with the aid of four different techniques: pollen size measurement, flow cytometric analysis of nuclei isolated from germinated and non germinated pollen, investigation of the microsporogenesis and analysis of progeny. In ten of the 70 screened genotypes (B. dregei, B. pearcei, B. ‘Anna Christina’, B. ‘Bubbles’, B. ‘Florence Rita’, B. ‘Orococo’, B. ‘Rubaiyat’, B. ‘Spatflacier’, B. ‘Tamo’ and B276), large pollen were observed with a rather spherical than normal ellipsoidal shape. Flow cytometric data proved that these aberrantly shaped pollen were associated with 2n ploidy levels, although they were not always viable. Meiotic aberrations in these large pollen producers resulted mainly in dyads although also monads, triads and polyads were observed. Successful crosses were obtained with B. dregei, B. ‘Orococo’, and B276 as pollinators; DNA content had increased in all or a part of the progeny. The results show that the occurrence of 2n pollen is not a rare phenomenon in Begonia.     

低温处理对亚洲百合种球萌发及开花特性的影响

对4个亚洲百合品种的种球进行低温处理,观察了处理时间对不同品种不同规格的种球萌发及开花特性的影响。结果表明,普丽安娜与普莱托低温处理50d、瑞塔与艾德林娜低温处理36d时种球萌发迅速、整齐;花茎长度和第1花苞大小随着处理时间的延长呈先加长或增多,后缩短或减少的趋势,4个品种间效果不同,不同规格间效果接近;花苞数目和花期也随处理时间的延长有先增大或延长,后减少或缩短的趋势,且4个品种间、不同规格的种球间效果接近。