Infection and colonization of jojoba byGanoderma lucidum

In arid conditions in India,Ganoderma lucidum (Leyss: Fr.) P. Karsten was found to cause root rot diseases in jojoba (Simmondsia chinensis (Link) Schneider) plants. In the rainy season, 10–15-year-old jojoba plants growing in the proximity of aGanoderma-infectedAcacia tortilis tree, developed disease symptoms. Twigs of affected plants started drying from the top of the branch; leaves turned yellowish brown and finally abscissed; plants dried up within 1 to 3 months. Basidiocarps developed from decaying roots near the collar region and produced colored stalks and fruiting caps. Pathogenicity of the fungus was established by keeping the infected root segments in direct contact with roots of healthy jojoba plants. Root rot symptoms were expressed within 5 months in inoculated plants subjected to moisture stress.     

A Possible Mechanism of Action of the Chemopreventive Effects of Sarcotriol on Skin Tumor Development in CD-1 Mice

Sarcophine derivatives have been suggested to be chemopreventive in nature. One of its derivatives, Sarcotriol (ST), was investigated to study the skin cancer chemopreventive effects in female CD-1 mice. Three groups (control, promotion, initiation) of 30 female CD-1 mice each were taken. Carcinogenesis was initiated with 7, 12- dimethylbenz (a) anthracene (DMBA) and promoted with 12-O-tetradecanoylphorbol-13- acetate (TPA). One hour before treating with DMBA (200 nmol/100 μl acetone), control and promotion groups were treated with acetone (100 μl) and initiation group with ST (30μg/100μl of acetone). Beginning one week after initiation with DMBA, control and initiation groups were treated with acetone and promotion group with ST (30μg/100μl of acetone), one hour before treating with TPA (5 nmol/100 μl acetone). This was carried out twice a week for the next 20 weeks. The effects of ST on ³H-thymidine incorporation in epidermal DNA, the possible role of apoptotic proteins and COX-2 involved in the prevention of skin tumor development of CD-1 mice were investigated. Tumor incidence and multiplicity was found to be 100%, 73%, 100% and 8.2, 4.8, 9.7 in control, promotion and initiation groups respectively. ST treatment resulted in a significant (P < 0.05) inhibition in the incorporation of ³H-thymidine in epidermal DNA. The promotion group showed higher levels of caspase-3, -8 and –9 compared to the control. COX-2 expression was significantly lower (P < 0.05) in the promotion group as compared to the control. No significant difference in caspase-3, -8, -9 and COX-2 levels were observed in the initiation group compared to control. Together, this study confirms the chemopreventive effects of ST, and for the first time identifies the stage of carcinogenesis at which ST exerts its chemopreventive effect, and elucidates the mechanism possibly by inducing apoptosis and decreasing the COX-2 levels, contributing to its overall cancer chemopreventive effects in the mouse skin cancer model.     

Identification of diverse germplasm lines for agronomic traits in a chickpea (Cicer arietinum L.) core collection for use in crop improvement

Utilization of exotic and diverse germplasm is needed to enhance the genetic diversity of cultivars. Genetically diverse lines provide ample opportunity to create favorable gene combinations, and the probability of producing a unique genotype increases in proportion to the number of genes by which the parents differ. Representative core collections (10% of the entire collection) have been suggested as a means to identify useful parents for crop improvement programs. The chickpea core collection (1956 accessions) was evaluated for 14 agronomic traits in two seasons to identify diverse agronomically superior chickpea germplasm. Season (year) and genotypic effects were significant for 13 of the 14 traits, while genotype × season effect was significant for 8 traits. The desi, kabuli, and intermediate type chickpeas differed significantly for days to maturity, basal secondary branches, pods per plant, seed yield, and 100-seed weight. In comparison to controls, 12 accessions flowered early, 15 produced greater seed yield, and 29 had greater 100-seed weight. Based on days to 50% flowering, pods per plant, seed yield, and 100-seed weight, 19 desi, 15 kabuli and 5 intermediate type chickpea germplasm lines originating from 10 countries were selected. The selected desi accessions produced 8.5% more seed yield and had 32% larger seeds than the control cultivar Annigeri while the selected kabuli accessions yielded at par with control L 550 but had 84% larger seeds. The 39 selected accessions and two control cultivars (Annigeri and L 550) were grouped by their first five principal components (PCs) into three clusters. Cluster 1 consisted of early maturing large-seeded kabuli types, cluster 2 early and late maturing desi types, and cluster 3 late maturing intermediate and kabuli types. Clusters 2 and 3 accessions had small to medium sized seeds. These accessions can be used in chickpea breeding programs to develop high yielding desi and kabuli cultivars with a broad genetic base.     

Preliminary Studies on Cryopreservation of Vegetative Thalli of Some Economically Important Seaweeds of India

The effects of cryoprotectants and their concentrations, prefreezing temperature, equilibration time, thawing temperature, and the regenerative efficacy of cryopreserved vegetative thalli (apical tips) of Gracilaria corticata J. Agardh., Ulva lobata Duetzing, and Hypnea musiformis (Wulfar) Lamouroux were evaluated. The apical tips were suspended in various cryoprotective solutions and slowly cooled to ?40?C over a period of 4 h. After the slow cooling step, the suspensions were immediately immersed in liquid nitrogen (LN), which were thawed after 2 days. Both U. lobata and H. musiformis survived maximally in 10% DMSO, whereas 10% glycerol was found most suitable for G. corticata. A slow cooling temperature of ?40?C and thawing temperature of 40?C were found most suitable irrespective of the species. The equilibration time of 60 min was found most suitable for G. corticata, while 45 min was sufficient for both H. musiformi and U. lobata. Cryopreserved vegetative thalli were then successfully regenerated, though the survival was considerably reduced up to a period of 28 days after which it was stabilized.     

沙棘果采收后的管理及营养价值研究

沙棘(Hippopheae rhamnoides L.)是生长在高寒干旱地区的一种具有广阔开发前景的植物.因为它的药用价值,美容功效及保健作用,所以有很高的商业价值.这种小型的浆果极易腐坏,由于很酸所以不能在采摘后立即食用.因此,加工程序的研究是现在的当务之急,以确保能尽快地科学开发它的食用价值.1996年,印度Leh地区在实地研究实验室里首次完成了果实质量参数的评定、沙棘汁的提取和果实存储的研究.不同品种沙棘价值的合理利用技术将会标准化.     

Organophosphorus derivatives containing isatin-3-hydrazones as chemotherapeutants against fungal pathogens of sugarcane

A total of 20 novel organophosphorus derivatives have been synthesized by the reactions of O,O-diethylchlorophosphate/thiophosphate with isatin-3-(substituted benzoic acid/phenoxy acetic acid hydrazones). The derivatives have been characterized on the basis of analysis and spectral (IR and (1)H and (13)C NMR) data. Fungicidal activities of the derivatives against Colletotrichum falcatum , Fusarium oxysporum , and Curvularia pallescence have been evaluated. The screening results have been correlated with the structural features of the tested compounds. The greater potency has been observed with thiophosphates compared to phosphates, with substituted phenoxy acetic acid hydrazones compared to substituted benzoic acid hydrazones, and with substitutent Cl(-) attached to the aromatic ring compared to other substitutents. O,O-Diethylchlorophosphate compounds containing isatin-3-(4-chlorophenoxy acetic acid hydrazone) (IIe) and the compound containing two molecules of O,O-diethylchlorophosphate attached to isatin-3-(4-hydroxy phenoxy acetic acid) hydrazone (IIh) were proven to be more active than some prevalent commercial synthetic fungicides.     

Histopathological Observations in Guava Root during Wilting caused by Fusarium Species: A Scanning Electron Microscopy Study

Fusarium oxysporum and Fusarium solani are the two most destructive pathogens causing wilt disease in guava (Psidium guajava L.) commonly known as ‘super fruits’. These pathogens attack mainly on the root region of the plant and cause severe infection. In the present investigation the infection process was studied with scanning electron microscopy (SEM) and it was observed that the root region of the guava plant showed disintegration and necrosis in the epidermal layer, cortex tissue, and in vascular bundles, while the root region of a healthy sapling showed no such changes. The rupturing of the epidermal layer may show the entry of pathogens in the host tissue through the secretion of toxic enzymes/metabolites. These toxins have great potential to cause wilting symptoms in guava plants in the form of necrosis. Wilt disease causes huge losses in guava production in both tropical and subtropical countries. Therefore, there is a need to find the responsible factors. The present study is an attempt to understand the interaction mechanism of phyto-pathogens causing wilt disease.     

Development of a technique for in vitro unpollinated ovary culture in rice, Oryza sativa L.

A simple and efficient technique for in vitro unpollinated ovary culture in rice which is also applicable for indica genotypes was developed for breeding and genetic studies. Sampling explants at the auricle distance of 7–12 cm between the two uppermost leaves of a tiller, providing a chilling pretreatment and ovaries with 1/3 of the hulls intact gave optimum response to culture. For callus induction with the spontaneous breaking of ovaries, N₆ media supplemented with NAA (2 mg/l) and DMSO (0.6–0.8%) gave a mean PCI value of 3.8% and range of 0.8–12.5% among genotypes. Media combining 2,4,5-T or 2,4-D with NAA in N₆ medium also has reasonably good callus induction. For calli induced inside, 2,4-D (0.2–0.5 mg/l), NAA (2 mg/l) and KT (1 mg/l) contained media were superior. The maximum green plant regeneration (PPR) of 77.3% was found with the medium containing NAA 0.25 mg/l, IAA 0.5 mg/l and KT 2.0 mg/l. Significant genotype, medium and their interaction effects for per cent ovary survival and callus induction were observed. This revised version was published online in August 2006 with corrections to the Cover Date.