3,5,4′-trihydroxystilbene as a phytoalexin from groundnuts (Arachis hypogaea)

Cis and trans-resveratrol (3,5,4′-trihydroxystilbene) have been isolated from the infected hypocotyls of Arachis hypogaea and implicated as phytoalexins.     

The effects of Cercospora leaf disease on the growth of groundnuts (Arachis hypogaea) in Nigeria

Three experiments with five alternately-branched and one sequentially-branched cultivar of groundnuts are described. Spraying to control Cercospora leaf spot disease doubled the leaf area duration and increased the total weight of a plant by about 65 %. Spraying increased the weight of kernels per plant but in the alternately-branched cultivars also increased the weight of stem and leaves. The proportion of the total dry weight in the kernels in the alternate cultivars was hardly changed by spraying. The sequentially-branched cultivar gave the same increase in total dry weight when sprayed but spraying resulted in a larger increase in the dry weight of kernels. The sequentially-branched cultivar, with few initials for vegetative growth, did not give the same increase in leaf growth.     

The occurrence of Indian peanut clump,a soil-borne virus disease of groundnuts (Arachis hypogaea) in India*

A disease characterised by severely stunted plants with small dark green leaves was found in groundnut (Arachis hypogaea) in sandy soils in Punjab State, India. The disease occurred in patches in the field and reappeared in the same positions in succeeding groundnut crops. Plants infected early did not produce mature pods. Seeds sown in soil collected from infected fields produced plants with typical disease symptoms. Phaseolus vulgaris cv. Local and Chenopodium quinoa were found to be good diagnostic hosts. The disease was shown to be caused by a rod-shaped virus c. 24 nm in diameter with predominant particle lengths of c. 249 and 184 nm when stained in uranyl acetate. The virus, named Indian peanut clump virus (IPCV), resembled peanut clump virus (PCV) reported from W. Africa in symptomatology on groundnuts, particle morphology and soil-borne nature. However, it is not serologically related to two W. African PCV isolates tested, or to tobacco rattle (PRN and CAM strains) or pea early browning virus (Dutch isolate) in microprecipitin, enzyme linked immunosorbent assay and immunosorbent electron microscopy tests.     

The Deamidase of Groundnut Plants (Arachis hypogaea)

The deamidase enzyme system present in extracts of groundnutplant tissues has been studied. The distribution of the enzymewithin the different organs of the plant were determined, andsome of the properties of the enzyme present in leaf extractsare recorded. From its substrate specificity the enzyme is probablybest regarded as a -methyleneglutaininase, although it catalysesthe hydrolysis of glutamine at about one-fifth of the rate of-methyleneglutamine. The enzyme may play an important role inthe over-all nitrogen metabolism of the plant, as well as controllingthe relative concentrations of -methyleneglutamine and -methyleneglutamicacid in the different organs. The properties of the enzyme havebeen compared with those recorded in the literature of glutaminasesand asparaginases, and certain common features are apparent.The new deamidase was, however, more stable to certain denaturingtreatments than were the other types of deamidase.     

花生根瘤菌群体遗传多样性和系统发育研究

利用16S rRNA RFLP,16S rRNA序列分析和16S－23S IGS PCR RFLP技术对43株花生根瘤菌和来自其他种属的15个参比菌株进行了群体遗传多样性和系统分析。16S rRNA PCR RFLP分析结果表明,所有供试花生根瘤菌均属于慢生根瘤菌属,在系统发育上与B.japonicum的亲缘关系最近,具有相同的16S rRNA RFLP基因型,而与B.elkanii相对较远。16S rRNA 序列分析结果表明,供试花生根瘤菌在系统发育上更接近于B.liaoningense,序列间差异小于1％,而B.liaoningense在系统发育上与B.japonicum相距很近,其序列间差异小于1％,16S－23S rRNA IGS RFLP分析结果表明,尽管花生根瘤菌与B.japonicum和B.elkanii的亲缘关系很近,但在71％的相似性水平上供试花生根瘤菌仍各自聚为一群,并可进一步分为A、B、C和D4个亚群,该分群还明显反映了地理因素对群体遗传多样性和系统发育的影响。     

A simplified methodology for purification of peanut (Arachis hypogaea) agglutinin

The agglutinin from peanut (Arachis hypogaea) was readily isolated by affinity chromatography on acid-treated Sepharose 6B. The recovered lectin (50 mg/100 g seeds) appeared as a single band of Mr 32,000 on gel electrophoresis and its specific haemagglutination titre on desialylated human A red blood cells was very high (2(15)).     

花生成熟花粉的超微结构

花生（Arachis hypogaea L．）成熟花粉为二细胞型,具3个萌发沟,少数有4个。外壁呈蜂窝状。花粉壁由覆盖层、基粒棒、外壁内层及内壁构成。线粒体嵴密集、相互平行,脂体被粗面内质网包围。粗面内质网与外核膜相连,亦与线粒体相连。高尔基体甚少。营养核无核仁及染色质,与生殖细胞相连形成雄性生殖单位（male germ unit）。生殖细胞锤形、有壁,见一末端延伸成长尾状（长8μm）。细胞质含核糖体、线粒体、微管,未见体。在有些生殖细胞核内观察到具双层膜、少量嵴及深色内含物的球形结构,其米来源及本质尚不知,有待进一步研究确定。     

花生衰老进程的研究

通过对鲁花11号和辐8707 2个高产花生品种的衰老进程研究表明：花生衰老具有地上部（叶片）渐进衰老和整株衰老的双重特点。花生从始花至花后60d左右为地上部（叶片）渐进衰老期：此期主茎高、侧枝长、分枝数、主茎、侧枝绿叶数、叶面积、茎、叶干重迅速增加,并接近或达到最大值,主茎及侧枝基部叶片逐渐由下向上开始衰老死亡,饱果开始出现,根系活力、固氮酶活性逐渐升高至接近最大值,始花后60－90d为整株缓衰期,此期地上部茎叶生长基因停止,逐渐开始衰老死亡,主茎、侧枝绿叶数开始减少,生殖体（荚果）干重迅速增长,根系活力、固氮酶活性缓慢降低;始花后90d以后称为整株速衰期,此期主茎、侧枝绿叶迅速减少,地上部迅速衰老死亡,生殖体（荚果）干重缓慢增长,根系活力、固氮酶活性迅速降低。地上部（叶片）渐进衰老期与开花及大量荚果形成相对应,整株缓衰期伴随着荚果迅速增重,整株速衰期与荚果缓慢增重一致。     

Histochemical specificity of beta-galactose binding lectins from Arachis hypogaea (peanut) and Ricinus communis (castor bean)

Previous histochemical studies have demonstrated disparities in the binding of two lectins with a nominal specificity for terminal beta-D-galactose. Biochemical studies have shown that the most complementary structure for binding peanut agglutinin (PNA) is the terminal disaccharide Gal-(beta 1----3)-GalNAc, whereas the most complementary structure for binding Ricinus communis agglutinin I (RCA I) is the terminal disaccharide Gal-(beta 1----4)-GlcNAc. However, it is not known if only these differences in affinity account for the different histochemical staining reactions observed on tissue sections. In the present study we compared the staining patterns of PNA and RCA I by inhibiting in situ the binding of each lectin conjugated to horseradish peroxidase (HRP) with increasing concentrations of unlabeled PNA or RCA I. The PNA-HRP conjugate did not stain most tissue sites suspected of containing an abundance of glycoconjugates with terminal Gal-(beta 1----4)-GlcNAc. Moreover, unlabeled PNA failed to significantly inhibit strong RCA I-HRP staining in these sites. In loci thought to contain variable amounts of glycoconjugates with terminal Gal-(beta 1----3)-GalNAc, unlabeled RCA I decreased PNA-HRP reactivity only slightly or not at all, whereas weak to strong RCA I-HRP staining was diminished or abolished by unlabeled PNA. The results suggest that PNA staining is restricted to glycoconjugates with terminal Gal-(beta 1----3)-GalNAc. RCA I apparently reacts most strongly with glycoconjugates having the terminal disaccharide Gal-(beta 1----4)-GlcNAc, but also stains sites containing a moderate to abundant amount of glycoconjugates with the terminal Gal-(beta 1----3)-GalNAc sequence.     

The structure of Bowman-Birk type protease inhibitor A-II from peanut (Arachis hypogaea) at 3.3 A resolution

The structure of Bowman-Birk type protease inhibitor (A-II from peanut) is described at 3.3 A resolution. The molecules form a tetramer with 222 local symmetry in our crystals. Each monomer has an elongated shape with approximate dimensions of 45 X 15 X 15 A and consists of two distinct domains. The three-dimensional structures of the two domains are similar and are related by the intramolecular approximate twofold rotation axis. The two independent protease binding sites protrude from the molecular body on opposite sides. A scheme for the molecular evolution of the double-headed Bowman-Birk type protease inhibitors is proposed, based on the three-dimensional structure.     

Micropropagation in Peanut (Arachis hypogaea L.)

Multiple shoots in Arachis hypogaea L. could be induced from the de-embryonated cotyledons (DC), embryo-axes (EA) and mature whole seeds (MWS) in MS medium supplemented with different levels of benzylaminopurine (BAP). DC was the most suitable explant with 57.9 % induction and more than 40 shoots per explant in 31.6 % of cases. Though EA and MWS had high percent induction at or above 30 mg dm^–3 BAP, only 10 – 14 shoots per explant were observed. In DC, multiple shoots were confined to the proximal end and in EA they originated from the axillary bud region. Histological studies on DC confirmed the origin of shoots from the region of attachment with the embryo. Shoots could be rooted in MS medium containing 2 g dm^–3 charcoal and 200 mg dm^–3 casein hydrolysate. Sixty percent of the rooted plantlets could be established in the field.     

Activity of acid and alkaline phosphatases (intracellular and extracellular) in rhyzosphere fungi from Arachis hypogaea (Papiloneaceae)

The potential role of the fungi, isolated from the peanut rhizosphere, in the production of extracellular and intracellular acid and alkaline phosphatase, was evaluated in vitro. Acid and alkaline extracellular phosphatases showed the highest activities, and the Penicillium species were the most efficient in their production. The correlation analysis showed that extracellular acid and intracellular acid phosphatase produced by Aspergillus niger A. terreus, Penicillium sp. y P. brevicompactum were negatively correlated; while the extracellular and intracellular phosphatase activities, were positively correlated. The extracellular acid phosphatase activities produced in vitro by majority of fungi assayed, were not correlated with the acid phosphatase activity present in the peanut soil rhizosphere. Nevertheless, the extracellular alkaline phosphatase activities produced in vitro, were negatively correlated with the extracellular alkaline phosphatase activities present in the rhizosphere. The ability of phosphatase production by fungi isolated from peanut rhizosphere suggests they have great potential to contribute to the P mineralization in this zone.     

Aflatoxin-producing Potential of Isolates of the Aspergillus flavus-oryzae Group from Peanuts (Arachis hypogaea)

Seventy-eight samples of farmer stock peanuts, representing peanuts grown in nine different geographical areas during 1964, were assayed for aflatoxin and examined for associated microflora. Only two samples contained more than 50 ppb of aflatoxin. Infestation by members of the Aspergillus flavus-oryzae group varied from 35 to 100% of the kernels per area and from 1 to 100% of the kernels per sample. Aflatoxin production by individual isolates ranged from 0 to 349,143 ppb under the test conditions employed. In general, the isolates produced 8 to 10 times more B₁ than B₂, and no isolate producing aflatoxins G₁ or G₂ was found. The importance of proper postharvest handling of peanuts is emphasized by the prevalence of isolates of A. flavus-oryzae capable of producing aflatoxins on farmers stock peanuts.