西部沙樱枝条愈伤组织诱导、增殖及分化培养

以西部沙樱一年生枝条为材料,研究不同激素配比条件下外植体愈伤组织的诱导、增殖及分化诱导。结果表明:西部沙樱茎段在2,4-D 0.5 mg/L+6-BA 0.5 mg/L+3%蔗糖+0.6%琼脂(pH 5.75)的MS培养基上可诱导出愈伤组织;愈伤组织增殖的最佳培养基为MS+2,4-D 0.5 mg/L+6-BA 1.0 mg/L+3%蔗糖+0.6%琼脂(pH 5.75);愈伤组织分化的最佳培养基为MS+NAA 0.3 mg/L+6-BA 1.0 mg/L+3%蔗糖+0.6%琼脂(pH 5.75),经分化可获得无性系芽,继而产生丛生苗。西部沙樱愈伤诱导及分化的成功为西部沙樱资源的保护、开发和利用提供了理论依据和技术保障。     

腊花组培快繁体系研究

为探讨最适初代诱导、增殖继代生根的培养基配方,建立腊花的组织培养技术体系,以腊花嫩茎尖为实验材料,采用MS培养基,向培养基中添加不同配比组合的KT和NAA,对腊花进行初代诱导培养;设置6-BA和NAA不同激素浓度组合进行增殖培养;选用1/2MS培养基为腊花生根培养的基础培养基,添加IBA不同浓度配比培养实验。最佳初代诱芽培养基为MS+ KT 3.0 mg/L+ NAA 0.2 mg/L+琼脂6.2 g/L+蔗糖30 g/L,pH 5.8,诱导率达88.8%。最佳增殖培养基为MS+ 6-BA 1.0 mg/L+ NAA 0.1 mg/L+ 琼脂6.2 g/L+蔗糖30 g/L,pH 5.8,增殖系数为3.6。最佳生根培养基为1/2MS+ IBA 0.6 mg/L+琼脂6.2 g/L+蔗糖30 g/L+0.1 g/L活性炭,pH 5.8,生根率100%。     

组织培养快速繁殖龙翅海棠

龙翅海棠的组培可以幼嫩叶片作外植体,通过诱导形成愈伤组织分化不定芽的途径,建立无菌系,获得再生植株.最适诱导分化培养基为Ms 1mg/L6-BA 0.1 mg/L NAA 3%蔗糖 0.6%琼脂;最适增殖培养基为:Ms 0.8mg/L6-BA 0.08mg/L NAA 3%蔗糖 0.6%琼脂;最适生根培养基为:1/2MS 0.08mg/L NAA 0.02mg/LIBA 3%蔗糖 0.6%琼脂;最适移栽基质为河沙∶珍珠岩=2∶1.增殖周期为35d.     

凉都红香椿外植体快繁体系的研究

以贵州凉都红香椿成熟叶片和无菌苗叶片为材料,筛选可用于诱导叶片再生形成植株的愈伤组织诱导和分化的培养基分别为:MS+0.15 mg/L TDZ+0.3 mg/L NAA+1.0mg/L KT+3%蔗糖+7g/L琼脂和MS+0.1mg/L 6-BA+0.5mg/L KT+0.1mg/L NAA+3%蔗糖+7g/L琼脂;同时筛选到以成熟香椿枝条为材料诱导腋芽生长的最适培养基为:MS+0.2mg/L GA3+0.02mg/L+3%蔗糖+7g/L琼脂。另外,研究还确定了香椿成熟叶片和枝条外植体的最佳消毒条件为:75%酒精处理45s,0.1%升汞灭菌6～8min后,用无菌水冲洗4～6次可降低外植体的污染率。     

铁皮石斛组织培养及快繁技术研究

为建立铁皮石斛快繁技术体系,给生产提供参考,研究了铁皮石斛组织培养过程中的灭菌方法、腋芽诱导、原球茎的诱导、增殖与分化的最佳培养基配方。以铁皮石斛成熟茎段为外植体,探讨1/2MS培养基或MS培养基中添加不同浓度的激素对铁皮石斛组织培养过程中各生长、分化阶段的影响。研究表明,腋芽诱导最适宜培养基的配方为MS+ 6-BA 2.0 mg/L+ NAA 0.5 mg/L,诱导率达91.28%,平均芽数达2.34;原球茎诱导的最适宜培养基为1/2MS+ 6-BA 0.5 mg/L+NAA 0.5 mg/L+2,4-D 1.0 mg/L,诱导率可达66.67%;原球茎增殖最佳培养基为1/2MS+ 6-BA 3.0 mg/L+NAA 0.3 mg/L,原球茎分化最适宜培养基为1/2MS+ NAA 1.0 mg/L+ 6-BA 3.0 mg/L+ KT 1.0 mg/L,最适宜生根的培养基配方为1/2MS+NAA 2.0 mg/L+ AC 0.5 g/L。     

务川几种野生百合的组织培养

采用正交试验的方法,在MS固体培养基上研究不同浓度蔗糖、6-BA及NAA对淡黄花百合、文山百合及野百合等3种务川野生百合芽增殖的影响,结果表明:淡黄花百合芽增殖的最佳培养基应为:MS +0.5 mg/L 6-BA +0.5 mg/L NAA+4％蔗糖,文山百合的最佳培养基应为:MS +0.5～1.0 mg/L 6-BA +0.5 mg/L NAA +3％蔗糖;野百合芽增殖的最佳培养基应为:MS+ 0.5 mg/L 6-BA+0.1 mg/L NAA+(2％ ～3％)蔗糖.     

三种植物生长调节剂对月季离体再生的影响

为了提高月季遗传转化的体细胞胚胎的植株再生率,以月季B103 (Rosa spp.)无菌苗为材料,探究不同浓度的细胞分裂素6-BA、KT、TDZ对植株生长的影响,并以优化的培养基EB和ET对成熟的月季B103体胚进行再生诱导。结果表明：添加KT的培养基(RK)上的无菌苗全部死亡,添加6-BA (RB)和TDZ(RT)的两组生长正常,最佳培养基为MS+NAA 0.05 mg/L+GA33.0 mg/L+6-BA/TDZ 0.5 mg/L+3%蔗糖+0.7%琼脂pH=5.7。成熟月季体胚在培养基MS+NAA 0.05 mg/L+GA33.0 mg/L+TDZ 0.5 mg/L+3%蔗糖+0.7%琼脂p H=5.7上诱导分化,30 d内再生出数量最多的正常植株,再生率为20%。ET组分化出丛生状态的子叶,再生率高于20%。本研究表明ET2可诱导月季细胞分化出正常再生植株。     

铁线莲‘水晶喷泉’茎段组培再生体系的建立

本研究以铁线莲品种‘水晶喷泉’(Clematis Crystal Fountain’Fairy Blue’)的带芽茎段为初始外植体,通过研究灭菌时间、激素浓度配比、基础培养基类型等因素对茎段腋芽的诱导、增殖、再生苗生根的影响,从而建立该品种从外植体—腋芽诱导—不定芽增殖—生根得到完整的植株再生体系。结果表明：最佳灭菌条件为5%次氯酸钠溶液灭菌10 min,污染率为22.2%,成活萌芽率为44.5%;带芽茎段诱导腋芽最适培养基为MS+6-BA 1.0 mg/L+NAA 0.05 mg/L+蔗糖30 g/L pH值为6.0～6.2,6-BA/NAA比值为20,诱导率为100%,此时苗生长良好且株高较高;腋芽增殖最适培养基为DKW+6-BA 2.0 mg/L+NAA 0.05 mg/L+蔗糖30 g/L pH值为6.0～6.2,6-BA/NAA比值为40,增殖系数为5.6;最佳生根培养基为DKW+IBA 1.0 mg/L+蔗糖30 g/L pH值为5.7,生根率可达94.4%,本研究可为铁线莲品种‘水晶喷泉’的组织培养、规模化种植提供相关资料和遗传转化体系建立提供了科学依据。     

野生蒙古韭组培快繁体系的建立

蒙古韭属于葱科葱属,是一种具有营养价值、饲用价值、药用价值和生态价值的野生植物资源。用野生蒙古韭的鳞茎作为外植体接入诱导愈伤培养基(MS+1 mg/L NAA+2 mg/L 6-BA+30 g/L蔗糖+8 g/L琼脂,pH 5.2)中,经过40 d培养,可萌发愈伤组织和丛生芽;放入诱导分化培养基(MS+1 mg/L NAA+1 mg/L6-BA+30 g/L蔗糖+6 g/L琼脂,pH 5.2)中,增殖3~5代,陆续获得大量的不定芽;诱导生根培养基为1/2MS+0.5 mg/L NAA+0.2 mg/L 6-BA+30 g/L蔗糖+6 g/L琼脂(pH 5.2),约20 d左右可生根,每棵小苗3~4条根;幼苗移栽成活率约80%,可以短时间内获得大量的蒙古韭幼苗。蒙古韭组培快繁体系的建立为下一步蒙古韭重要基因的功能验证和蒙古韭转基因育种提供理论基础,也为蒙古韭分子生物学相关研究提供材料。     

不同生长调节剂对金丝梅组培快繁的影响

本研究以云南野生金丝梅(Hypericum patulum)带休眠芽的茎段为外植体,研究了不同植物生长调节剂对其离体培养的影响,以建立金丝梅离体快繁技术体系。研究结果表明,腋芽诱导的适宜培养基为MS+6-BA 2.0 mg/L+NAA 0.1 mg/L,诱导率可达90%;适合腋芽增殖的培养基为MS+6-BA 1.0 mg/L+NAA 0.1 mg/L+GA30.1 mg/L,增殖系数可达5.12;最佳生根培养基为1/2MS+IBA 0.5 mg/L+活性炭0.1 g/L,生根率为96.69%。炼苗移栽到草炭土∶珍珠岩=2∶1的基质中,成活率达100%,移栽到苗圃后成活率为100%。研究结果为金丝梅高效快速繁殖以及优良品种选育提供科学依据。     

内蒙古牛病毒性腹泻病毒血清学调查

为了解内蒙古自治区集约化养牛场病毒性腹泻的感染情况。用致细胞病变型牛病毒性腹泻病毒毒株制备中和抗原,通过中和实验对采自乌兰浩特、巴彦淖尔和呼和浩特地区6个集约化奶牛场的509份血清进行了牛病毒性腹泻病毒抗体检测。结果表明：共检出阳性血清297份,6个牛场的牛病毒性腹泻病毒血清阳性率分别为55.10%、38.80%、45.50%、50.00%、77.80%、33.33%;乌兰浩特、巴彦淖尔、呼和浩特这3个地区的平均阳性率分别为77.80%、48.70%、33.33%,总血清阳性率为58.35%。说明内蒙古地区存在牛病毒性腹泻病毒的感染,应采取相应的措施净化牛场。     

In-vitro Fertilization of Ovules of Some Species of Brassicaceae*

The method of in-vitro fertilization of ovules can be successfully applied to various species of Brassincaceae. Mature embryos and plants were obtained after in-vitro pollinating the ovules of Arabis caucasica, Brassica napus, B. oleracea var. sabellica (kale), B. oleracea var. italica (broccoli), Diplotaxis tenuifolia, Moricandia arvensis and Sisymbrium Loeselli. In the case of Sinapis alba fertilization and embryo development did not occur. The same method has been successfully used for obtaining hybrid immature embryos at different stages of development from crosses between B. napus X D. tenuifolia, B. napus X M. arvensis, B. oleracea var. italica X D. tenuifolia, D. tenuifolia x B. napus, D. tenuifolia. X M. arvensis and D. tenuifolia X S. Loeselli. The present findings show that in-vitro pollination of ovules of various species of Brassicaceae makes it possible to (a) perform the whole process of fertilization and embryogenesis; and (b) obtain intergeneric hybrid embryos.     

The potential role of PR-8 gene of apple fruit in the mode of action of the yeast antagonist,Candida oleophila,in postharvest biocontrol of Botrytis cinerea

Several pathogenesis-related (PR) genes of apple have been cloned and their response to different pathogens has been studied. Different PR genes, however, may have a variable response depending on the specific organ or tissue as well as microbe. The objective of the current study was to characterize the expression of specific apple PR genes in fruit tissues in response to the antagonistic yeast, Candida oleophila (a common postharvest biocontrol agent), and the fungal pathogen, Botrytis cinerea (a major postharvest pathogen). Apple PR-5 and PR-8 gene expression was characterized in fruit in response to C. oleophila and B. cinerea. Results indicated that PR-8 expression was significantly elevated in response to both fungi. In contrast, neither C. oleophila nor B. cinerea treatment markedly affected PR-5 expression. The PR-8 gene was then synthesized and cloned into a Pichia pastoris expression system to study the antifungal activity of the PR-8 protein against B. cinerea both in vitro and in vivo. Collectively, the PR-8 gene of apple is associated with the response to B. cinerea infection, and may play a role in the mechanism by which C. oleophila effectively inhibits B. cinerea disease in apple fruit, namely by the induction of this specific host PR gene.     

灰分对煤自燃特性影响的实验研究

为了研究灰分对煤自燃能力的影响作用,利用绝热氧化实验装置对不同灰分含量煤样进行升温氧化实验,采用R₇₀、T_CPT、B 3种指标表征灰分含量对煤样自发氧化过程的影响。结果表明：1）灰分含量越大,煤样低温氧化阶段温升速率越小,温升加速点温度越高,煤样的自发氧化过程越慢,煤越不易自燃;灰分含量大于40%后,煤自燃倾向性快速减弱。温升加速点是反应微观信息的零活化能温度的宏观累计结果,具有直观且滞后的特点。灰分越大,滞后越明显,温差越大。2）R₇₀、T_CPT、B 3种指标与灰分关系表现为二次函数。R₇₀和T_CPT两种指标显示灰分越大,自燃倾向性越弱,与实践经验相符。受水分权重影响,B指标显示煤样在灰分小于40%时,灰分越大,煤样自燃倾向性越强,这与实践经验相悖。因此,B在判定灰分对煤样自燃倾向性的影响时具有一定的局限性。     

Yield Performance of Wheat Isolines with Different Dosages of the Short Arm of Rye Chromosome 1

Translocations of the short arm of rye (Secale cereale L.) chromosome 1 (1RS) in wheat (Triticum aestivum L. cv. Pavon 76) are known to increase root biomass. Such an increase enhances water and nutrient uptake and may improve grain yield. Two greenhouse experiments and a field experiment were carried out at the University of California, Riverside, in 2012 and 2013 under well‐watered and terminal drought treatments to evaluate phenotypic characters associated with varying dosages of 1RS, including grain yield. The genotypes used were cultivar Pavon 76 (R₀), Pavon 76/Pavon1RS.1AL (F₁ hybrid) with a single dosage of 1RS (R₁A), Pavon 1RS.1AL with two dosages of 1RS (R₂A), Pavon 1RS.1DL (R₂D) also with two dosages of 1RS and Pavon 1RS.1AL‐1RS.1DL (R₄AD) with four dosages of 1RS. There was a significant positive correlation between number of dosages of 1RS and root biomass. However, no correlation was found between root biomass and grain yield per plant. Drought in the field experiment reduced grain yield significantly. Under well‐watered field conditions, grain yield of R₂A (215.9 g plant^?1) was significantly greater than those of R₂D (191.8 g plant^?1) and R₄AD (161.7 g plant^?1). Also, grain yield of R₄AD was significantly less than those of F₁, Pavon 76 and R₂D under well‐watered conditions. Under drought field conditions, no significant differences were found among the genotypes for grain yield was found between F₁ (14.7 g plant^?1) and R₄AD (12.4 g plant^?1). Harvest index was significantly greater in well‐watered (44.2 %) than in drought (34.6 %) field conditions. On average, genotypes F₁ (42.3 %) and R₂A (40.6 %) had higher harvest index than R₂D (38.3 %) and R₄AD (35.5 %) in the field. Also, Pavon 76 (40.2) and R₂D (38.3) had higher harvest index than R₄AD. Drought tolerance was lowest for R₄AD due to its relatively lower grain yield potential. In general, Pavon 1RS.1AL carrying two dosages of 1RS showed higher grain yield under wet treatments. Pavon 1RS.1AL‐1RS.1DL carrying four dosages of 1RS produced the largest shoot and root biomasses, but the least grain yield.     

Evolutionary studies of the soybean: the frequency and distribution of alleles among collections of Glycine Max and G. Soja of various origin

Summary Allelic frequencies at 10 loci common throughout the genus Glycine subgenus Soja were determined for 27 geographical area-species samples. The samples included 366 accessions of Glycine soja, the wild soybean, and 193 accessions of G. max, the domesticated soybean, from the USDA Soybean Germplasm Collection. The data indicate that the alleles for grey pubescence (t ₁), low seed coat peroxidase level (ep), and blunt pubescence tip (pb) probably arose as mutations during the domestication of G. max. The remaining seven loci studied(Fr, Pa ₁, Pa ₂, Fg ₁, Fg ₂, Fg ₃and Fg ₄)are polymorphic throughout the subgenus Soja; differences among collections of G. max and G. soja seem to be the result of differing selection pressures. A cluster analysis of allelic frequencies reveals two distinct groups within the subgenus corresponding to G. soja and G. max, Semi-wild accessions of G. max, while morphologically more similar to cultivated plants, clustered with samples of G. soja. The semi-wild accessions examined are thought to have arisen via hybridization between G. soja and G. max.Joint contribution: North Central Region, Agricultural Research, Science and Education Administration, U.S. Department of Agriculture, and Journal Paper No. J-9868 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa 50011; Project 2107.     

Associations and genetics of three components of slow rusting in leaf rust of wheat

Summary Forty F₆ lines, the two parental lines, and a susceptible check cultivar of wheat (Triticum aestivum L.) were inoculated in the young flag leaf stage with leaf rust (Puccinia recondita f.sp. tritici) and evaluated for latent period, receptivity, and uredinium size in a greenhouse experiment. Genotypic (r_g) and phenotypic (r_p) correlations between latent period and uredinium size were –0.81 and –0.62, respectively. A negative correlation (r_g=–0.50, r_p=–0.41) was found between latent period and receptivity and a positive correlation (r_g=0.28, r_p=0.26) between uredinium size and receptivity was found. Area under the disease progress curve (AUDPC) and final rust severity (FRS) obtained from a subsequent field study with common entries were negatively correlated with latent period and positively correlated with uredinium size. Correlations of receptivity with both AUDPC and FRS were not significant. The distributions of F₆ family mean uredinia size and latent period were continuous between slow rusting and fast rusting parents: however, the distribution for receptivity was discrete. Narrow-sense heritability estimates were 63%, 57%, and 47% for uredinium size, latent period, and receptivity, respectively. Estimates of the minimum number of effective factors were three for latent period and three or four for the uredinium size and receptivity. The components are controlled by closely linked genes or due to pleotropic effects of the same gene.Abbeviations AUDPC - Area under the disease progress curve - FRS - Final rust severity     

Inheritance of resistance to race F of broomrape in sunflower lines of different origins

A new race F of broomrape overcomes all known resistance genes in cultivated sunflower, but recently, sources of resistance against race F have been developed. The objective of the present research was to study the inheritance of resistance to race F in crosses between 12 resistant sunflower breeding lines, derived from three different sources of resistance, and the susceptible male‐sterile line P‐21. Parental lines and F₁, F₂, F₃ and BC₁ generations were evaluated for broomrape resistance. Segregations in the F₂ and BC₁ to resistant parent approached resistant to susceptible ratios of 1: 15 and 1: 3, respectively, in most of the crosses, suggesting a double dominant epistasis. However, segregations of 3: 13 and 1: 1 for F₂ and BC₁, respectively, indicating a dominant‐recessive epistasis, were also found. The F₃ data confirmed these results. Owing to the recessive nature of this resistance, it must be incorporated into both parental lines for developing resistant hybrid cultivars.     

Analysis of mode of inheritance of Fusarium wilt resistance in castor (Ricinus communis L.)

Castor (Ricinus communis L.) is an important industrial oilseed crop grown worldwide. Wilt caused by Fusarium oxysporum f.sp. ricini is a devastating disease in castor. The inheritance mode of wilt resistance was investigated. The F₁, F₂ and backcross generations of four crosses involving four resistant and three susceptible parents were developed. The role of digenic (R¹ and R²) epistatic interactions on wilt resistance was confirmed. The 15 : 1, 9 : 7 and 13 : 3 ratios indicated duplicate dominant, duplicate recessive and dominant and recessive epistatic interactions, respectively. Castor parents used in the crosses exhibited varied inheritance modes. All generations of a cross exhibited similar inheritance mode when parents were comparable. However, generations varied in inheritance mode when parents were not comparable in inheritance mode. These results would have practical interest when decisions are required regarding the choice of parents and methodology in resistance and hybrid breeding. The results also provided a basis for investigating molecular genetics of wilt resistance mechanisms.     

Importance of storage temperatures in maintaining flavor and quality of mandarins

Mandarins suffer from short ‘flavor-life’ compared with other citrus species. The recommended minimum safe temperature for mandarin storage is 5-8 °C. However, because of continuing reductions in permitted chemical residues and increasing concern regarding decay development, mandarins are often shipped at much lower temperatures of 3-4 °C. In the last few years we noticed wide differences in responsiveness of mandarin varieties to chilling, and that the earliest indication of damage was a decrease in flavor acceptability. In the present study, we evaluated changes in flavor and quality of chilling-tolerant ‘Or’ and chilling-sensitive ‘Odem’ mandarins after 4 weeks of storage at 2, 5, or 8 °C followed by 3 days at 20 °C. Low storage temperatures resulted in loss of orange peel color in fruit of both varieties, which became paler and yellowish. The flavor of ‘Or’ mandarins was not affected by different storage temperatures, whereas ‘Odem’ showed severe flavor loss at low storage temperatures. GC-MS analysis of aroma volatiles revealed that changes of storage temperatures had no major effects on aroma volatile contents in ‘Or’ mandarins. However, in ‘Odem’ mandarins, storage at 2 °C caused accumulation of 13 volatiles, mainly terpenes and their derivates, whereas storage at 8 °C resulted in decreases of six volatiles, comprising five terpenes and one terpene derivative. Overall, we conclude that storage temperature is a fundamental factor affecting color and flavor of mandarins, and therefore it is crucial to define the optimal minimum safe temperature for each mandarin variety. Furthermore, massive accumulation of terpenes is most likely the cause for the decrease in flavor acceptability of ‘Odem’ mandarins after storage at low chilling temperatures.