花生体细胞胚胎发生的组织细胞学研究

成熟花生胚轴在MS 40mg/\L2,4-D 0.5mg/L KT培养基中可直接诱导产生体细胞胚，降低2，4-D的浓度，将诱导产生的体细胞胚组织块继代2-3次可诱导产生出米黄色颗粒状的胚性愈伤组织，继而产生体细胞胚。花生体细胞胚直接诱导起源于表皮或近表皮的细胞，其形成经历了跟合子胚相似的过程。花生胚性愈伤组织的细胞具有细胞小、胞质浓、核大、核仁明显，排列紧密的特点。经愈伤组织形成的体细胞胚以单细胞内起源方式发生。首先由体细胞胚单个原始细胞分裂形成2-细胞原胚，2-细胞原胚继续分裂成3-细胞原胚或4-细胞原胚，3-细胞原胚或4-细胞原胚继续分裂形成多细胞原胚，进一步发育形成一个完整的体细胞胚。     

Sodium azide induced high-oleic peanut (Arachis hypogaea L.) mutant of Virginia type

Less prone to oxidation than its conventional counterpart, high-oleic peanut (Arachis hypogaea L.) containing?≥?72% oleate and?<?8% linoleate is preferred by processors, seed sellers and consumers. Development of high-oleic peanut cultivars with suitable pod/seed size and shape may satisfy the need from food processors manufacturing whole kernel or halve products. In this study, a high-oleic Virginia type peanut mutant was identified through screening of a 15 mmol/L sodium azide mutagenized M3 population with near infrared spectroscopy. Sequencing of the mutated and wild type FAD2A/FAD2B genes detected 2 point mutations. The G448A mutation in FAD2A was the same as in previous reports, causing an amino acid change of D150N. G558A in FAD2B was a novel mutation, resulting in a stop codon and premature termination of protein synthesis. 16 promising lines with acceptable productivity and pod/seed characters have been tentatively bred, which will be evaluated further in yield tests with replications after seed increase.

     

The genome donors of the groundnut/peanut (Arachis hypogaea L.) revisited

Arachis hypogaea, the cultivated groundnut is a tetraploid with an AABB genomic constitution. The available literature on the origin of groundnut reveals that there is general agreement that the cultivated groundnut has evolved from the wild tetraploid species A. monticola, with which it crosses freely to produce fertile hybrids. However, the issue of actual diploid ancestors of A. monticola is still unresolved. Both cytogenetic and molecular evidences support A. duranensis being the most probable progenitor and donor of the A genome to A. hypogaea. For the B genome, the cytogenetic evidence suggests A. batizocoi to be the most probable progenitor, but the RFLP banding pattern indicates that A. batizocoi is more distantly related to A. hypogaea than other species of section Arachis. RFLP banding pattern indicates A. ipaensis to be one of the closest species to A. hypogaea and the possible donor of the B genome. The present article critically analyzes the available data, which suggests that until an amphidiploid is produced synthetically between A. duranensis × A. ipaensis and crossed successfully with A. hypogaea to produce a fertile hybrid, this issue would remain unresolved. A. batizocoi would remain the most probable donor of the B genome because of its directly demonstrable cytogenetic affinity.     

Diagnosis of zinc deficiency in peanut (Arachis hypogaea L.) by plant analysis

Abstract

Critical values of zinc (Zn) concentration in young leaves Here established for the diagnosis of Zn deficiency in peanut by examining the relationship of Zn concentration in leaves to shoot dry matter (DM) at two growth stages of plants grown in pots of Zn deficient sand at seven levels of Zn supply (0, 67, 133, 200 267, 533, and 1067 μg Zn/kg soil). Zinc deficient peanut accumulated reddish pigments in stems, petioles and leaf veins in addition to the more common symptoms of Zn deficiency in plants. Zinc concentrations increased with increasing Zn supply in the blades of the youngest fully expanded leaf (YFEL) and in the blades of the leaves immediately older (YFEL+1) and younger (YFEL‐1) than it: they also increased with increasing Zn supply in the petioles of the YFEL+1 and YFEL and in the basal stem internode but their Zn concentrations Here always much lower than those in the blades. Critical Zn concentrations in the blades of the YFEL and YFEL+1 Here 8–10 mg Zn/kg DM at early pegging and mid pod filling: values for YFEL‐1 were similar but more variable. The blade of the YFEL is recommended for diagnosis of Zn deficiency in peanut and 8–10 mg Zn/kg DM as its critical value.     

Morphological and reproductive characterization of nascent allotetraploids cross-compatible with cultivated peanut (Arachis hypogaea L.)

Genetic Resources and Crop Evolution - Peanut improvement is limited by a narrow genetic base. However, this obstacle can be circumvented by incorporating phenotypic variability from wild, diploid...     

Non-rhizobial peanut nodule bacteria promote maize (Zea mays L.) and peanut (Arachis hypogaea L.) growth in a simulated crop rotation system

The term “Plant Growth Promoting Bacteria” or PGPB designates a diverse group of prokaryotic microorganisms that can increase plant growth by diverse mechanisms. Some PGPB are capable of colonizing root inner tissues and constitute endophytic populations. Incorporation of these microorganisms into agricultural practices may constitute a valid alternative to increase crop productivity in a sustainable and environmentally friendly production scheme, reducing the application of agrochemicals. In a previous work, we described the characterization of bacteria belonging to Pseudomonas, Enterobacter and Klebsiella obtained from surface sterilized peanut nodules. In addition, we showed that some of these isolates were able to promote several peanut growth and symbiotic parameters. Bounded to the results from this particular study, and considering their potential ability to interact with different plant species, in this work we assessed the effects of their inoculation in maize (Zea mays L.) under controlled conditions. Furthermore, we analyzed growth promotion in a simulated peanut–maize crop rotation system. Finally, we determined the plant growth promoting (PGP) properties present in the isolates. Results indicated that all bacteria are able to significantly promote maize and peanut growth, and that they also displayed plant growth promotion activity in maize growing in a peanut–maize crop rotation sequence.     

Silicon effect on growth,nutrient uptake,and yield of peanut (Arachis hypogaea L.) under aluminum stress

Abstract

The objective of this study was to investigate the effect of silicon (Si) on growth, nutrient uptake, and yield of peanut under aluminum (Al) stress. Peanut (Arachis hypogaea L. cv. Zhonghua 4) raised with or without Si (1.5?mM) in the growth chamber under 0 and toxic Al (0.3?mM) levels. Aluminum stress significantly decreased the biomass and root dry weight by 12.9% and 10.7%, and the pod yield, number of mature pod per plant and seed number of per pod by 16.7%, 10.7%, and 13.9%. The content of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) was significantly decreased, but that of Al increased markedly in shoots and roots of peanut after Al exposure at seedling, flower-needle and pod-setting stage. Under Al stress condition, Si application protected peanut by improving nutrient uptake at different growth stages and favoring the partitioning of dry mass to pod and the allocation of tissue N, P, K, Ca, and Mg to shoots and pod and decreasing Al uptake and accumulation.     

Reduced trigonelline accumulation due to rhizobial activity improves grain yield in peanut (Arachis hypogaea L.)

Abstract

Crop improvement for drought tolerance is critical for the future of crop production. The objectives were to examine the relationship between trigonelline (TRG) accumulation and yield traits in 10 peanut (Arachis hypogaea L.) genotypes inoculated with two commonly used nitrogen-fixing Rhizobium spp., and to evaluate a role of TRG on growth traits. TRG increased as a defensive metabolite in response to water deficit, but resulted in the reduction of the number of nodules and yield. Symbiotic rhizobial activity helped plants to improve yield particularly in a fully irrigated field rather than under reduced irrigation. TRG concentrations in genotypes (7 out of 10) increased under reduced irrigation as compared with those under full irrigation in two years. Mean number of nodules at maturity (120 days after planting) across genotypes under reduced irrigation were 89 in the control, 111 in Lift, and 161 in Histick treatments, among which Histick was significant (p < 0.05) for nodulation. Mean pod yields in the control, Histick, and Lift treatments were 1.69, 2.34 and 1.87 Mg ha^-1, respectively, under reduced irrigation. Under full irrigation, pod yields were 3.35 in the control, 4.50 in Histick and 3.41 Mg ha^-1 in Lift treatments, but were more significantly improved as treated with Histick than other treatments. Genotype ICGS-76 produced the highest pod yield (5.13 Mg ha^-1) as treated with Histick. All genotypes treated with Histick and Lift biosynthesized less TRG (decreased from 5.8 to 65.3% relative to the control) but produced larger numbers of pods (increased from 9.2 to 80.4% relative to the control), which resulted in substantially higher pod yields.     

cDNA clone of a putative peanut (Arachis hypogaea L.) trypsin inhibitor has homology with peanut allergens Ara h 3 and Ara h 4

Trypsin inhibitors are pathogenesis-related (PR) proteins, which play an important role in the plant defense mechanism against insects and pathogens. Peanut trypsin inhibitors are low molecular mass seed storage proteins. Like peanut allergens, they are stable to acid and heat, resistant to digestion, and can have a negative impact on human health. In peanut, five Bowman-Birk trypsin inhibitors (BBTI) have been isolated and amino acid sequences published. However, to date, no peanut BBTI sequence is available at both the cDNA and the genomic levels. The objectives of this investigation were (i) to synthesize degenerate oligonucleotides based on conserved regions of published amino acid sequences of BBTI, BII, and BIII; (ii) to isolate, sequence, and analyze at least one positive peanut trypsin inhibitor cDNA clone using the synthesized (32)P-labeled oligonucleotides as probes; and (iii) to determine its trypsin inhibitory activity. Thirty-two degenerate oligonucleotides DNA primers of 24 nucleotides each were synthesized based on the published amino acid sequences of peanut BBTI, and two were selected as probes to screen a peanut Lambda gt 11 cDNA library. Three putative positive clones were isolated, purified, and subcloned, and one was sequenced. Sequence analysis revealed a partial cDNA clone of 643 bp with a start codon. This clone shares 93 and 96% nucleotide sequence homology with peanut allergens Ara h 3 and Ara h 4 cDNA clones, respectively. A trypsin inhibitor assay revealed that peanut allergen Ara h 3 has a trypsin inhibitory activity of 11 238 TIA/mg protein. We concluded that peanut allergen Ara h 3 may also function as a trypsin inhibitor.     

Evaluation of genetic relationships among botanical varieties of cultivated peanut (Arachis hypogaea L.) using AFLP markers

Forty-four accessions of cultivated peanut (Arachis hypogaea L.) representing sixbotanical varieties of two subspecies along with three accessions ofthe wild relative A. monticola Krapov et Rigoni were evaluated for their genetic relationships using theAFLP marker technology. Fifteen AFLP primer pairs (EcoRI/MseI) generated 28distinct polymorphic markers that were employed to develop uniqueprofiles of all accessions and to construct a phenogram. The resultsshowed that the botanical varieties aequatoriana and peruviana werecloser to subspecies hypogaea than subspeciesfastigiata Waldr. to which they belong, and the wildA. monticola was notdistinct from the cultivated A.hypogaea. Although the extent of geneticdiversity in peanut is low compared to many other crops, our studiesshow that by employing the AFLP approach, sufficient DNA variationcan be detected in the cultivated peanut germplasm to conductevolutionary studies.     

Cobalt and molybdenum stimulate compounds of primary metabolism,nitrogen forms,and photosynthetic pigments in peanut plants (Arachis hypogaea L.)

Abstract

The objective of this study was to evaluate the effects of cobalt (Co) and molybdenum (Mo) doses in the treatment of seeds on the biosynthesis of nitrogen compounds, photosynthetic pigments, sugars, and production of peanut plants. The doses of Co and Mo used were 0, 2, 3, and 4?mL kg^?1 seed, which were applied immediately before sowing. Seeds treated with Co and Mo at a dose of 4?mL kg^?1 yielded peanut plants with higher concentrations of photosynthetic pigments, carotenoids, and sucrose in leaves. Application of Co and Mo doses also increased biological nitrogen fixation by increasing the concentration of allantoic acid, nitrate, ammonia, and amino acids in leaves. The concentration of total amino acids corresponded to most of the nitrogen compounds (on average 50%), followed by the concentrations of nitrate (35%), ammonia (11%), allantoic acid (7%), and allantoin (0.2%). Application of 4?mL kg^?1 increased the production of total amino acids compared with the control treatment. Pod yield was not affected by the Co and Mo doses; however, treatment of peanut seeds with 4?mL kg^?1 was the most viable alternative for increased production of primary metabolism compounds, nitrogen forms, and photosynthetic pigments in peanut plants. This study provides important information regarding the role of Co and Mo in the biological nitrogen fixation of peanut plants. Future experiments should be conducted using a dose of 4?mL kg^?1 with different genotypes to verify the potential for increasing peanut yield.     

Indirect competitive ELISA for determination of traces of peanut (Arachis hypogaea L.) protein in complex food matrices

An indirect competitive ELISA was developed allowing the detection of hidden peanut protein residues down to 2 ppm (micorgrams per gram) in various foods. The high-titer, peanut-specific polyclonal antiserum used recognized potentially allergenic proteins in both native and roasted peanuts. In the absence of a food matrix, extractable protein from roasted peanuts was detected at 104 +/- 13%. From various food items, peanut protein at > or =13 ppm was recovered between 84 and 126%, and at 2 ppm of peanut protein recovery was 143 +/- 6%. Intra- and interassay precision was <15%. In 5 of 17 commercial food products without declaration of peanut components, between 2 and 18 ppm of peanut protein was detected. This is the first assay based on commercially available reactants that allows the reliable determination of trace amounts of hidden peanut allergens in a variety of complex food matrices.     

花生品种间杂种F1代的SSR标记分析

以花育22号和Sunoleic95R为亲本配置杂交组合,获得杂种F1,利用SSR引物对亲本和杂种F1各单株进行扩增,分析其带型,辨别真伪杂种,并对亲本和杂种F1各单株的农艺性状、品质进行调查测定。结果表明：5对引物PM50 、PM179、 PM15、PM384和PM348对亲本、杂种F1各单株的分析结果是一致的,15个杂种F1单株,8株表现为母本带型,是伪杂种;7株表现为杂合带型或父本带型,即真杂种。但5对引物的带型表现存在明显差异,PM50 、PM179、 PM15、PM384表现为双亲互补带型, PM348表现为偏父本型。农艺性状和品质性状分析表明真杂种与伪杂种的籽仁重、侧枝长、亚油酸含量、油酸含量差异大,主茎高、蛋白质含量、脂肪含量差异较小。证实利用SSR标记辨别栽培种花生真伪杂种是可行的。     

Aflatoxin production in six peanut (Arachis hypogaea L.) genotypes infected with Aspergillus flavus and Aspergillus parasiticus, isolated from peanut production areas of Cordoba, Argentina

Aflatoxin contamination is one of the main factors affecting peanut seed quality. One of the strategies to decrease the risk of peanut aflatoxin contamination is the use of genotypes with resistance to Aspergillus infection. This laboratory study reports the resistance to Aspergillus infection and aflatoxin contamination of six peanut genotypes inoculated with 21 Aspergillus isolates obtained from the peanut production region of Cordoba, Argentina. The resistance was investigated in the seed coat and cotyledons of three resistant genotypes (J11, PI 337394, and PI 337409) and three breeding lines (Manfredi 68, Colorado Irradiado, and Florman INTA) developed at the Instituto Nacional de Tecnologia Agropecuaria (INTA), Manfredi Experimental Station, Cordoba, Argentina. Resistance to fungal colonization and aflatoxin contamination was found to be associated with seed coat integrity in the PI 337394, PI 337409, and J11 genotypes, whereas the INTA breeding lines such as Colorado Irradiado showed a moderate resistance and the Manfredi 68 and Florman INTA genotypes the least resistance. Furthermore, another type of resistance associated with cotyledons was found only in the PI 337394 genotype.     

The hydrophobic character of peanut (Arachis hypogaea) isoagglutinins

Peanut seed lectin (PNA) is widely used to identify tumor-specific antigens on the eukaryotic cell surface. In this work PNA was purified by affinity chromatography, using a column containing glutaraldehyde-treated human erythrocytes, whereas PNA isoforms were purified by hydrophobic interaction chromatography using Phenyl-Sepharose. The affinity-purified PNA and its isoforms consist of four equal subunits of 24.5 kDa each, all of which agglutinated human sialidase-treated erythrocytes equally well; however, differences in their relative thermostabilities and sugar specificities for lactose were observed. Fractions PNA-I and PNA-II possess higher affinity for lactose residues than the more hydrophobic isoforms III and IV. These findings suggest that the differences observed in PNA isoagglutinins are due to hydrophobic regions of the protein that influence the three-dimensional organization of the molecule as well as its thermal stability and sugar specificity.     

Adsorption of peanut (Arachis hypogaea, Leguminosae) proteins by activated charcoal

The binding of peanut protein allergens to activated charcoal (AC), used medically for gastric decontamination following the ingestion of toxic substances, was investigated for potential clinical application. Crude peanut extract (CPE) or purified peanut protein allergens Ara h 1 and 2 were co-incubated with AC under a variety of conditions followed by centrifugation to remove the AC and adsorbed protein. The resulting supernatant solution was analyzed for unadsorbed protein by gel electrophoresis and quantitative protein assay. The extent of protein adsorption by a known amount of AC was determined. Protein binding to AC was rapid and irreversible. The extent of adsorption was unaffected by pH, but was optimal near physiological salt concentrations. Denatured proteins, or those of larger molecular weight, required more AC than smaller or native proteins. The extent of protein binding increased with temperature, supporting the concept that protein molecules diffuse into vacant pores of appropriate size on the charcoal surface.