Growth, flowering and fruiting in vitro pineapple (Ananas comosus L.) in greenhouse conditions

The experiment was carried out in a greenhouse, located in Tehran city, Iran. The objectives of this study was to evaluate the effects of fertilizer and acidic soil on the foliar and radicular growth of micropropagated plantlets of the pineapple cv. Merr (Ananas comosus L.). We evaluated the growth of that genotype in five different ages of acclimatizing: 1, 2, 3, 4, 5 and 6 months in greenhouse. The hardening of plantlets increased length of shoot, leaf length and leaf number and slip production, accelerated flowering and fruit maturity, caused uniform flowering and fruit ripening, and had no effect on sucker development. When hardening plantlets were at least 60 to 70 cm tall and 10 to 12 months old, an inflorescence bud was observed to form in the center of the leaves. Flowers (light red in color) opened row by row over a period of about two weeks. When fruits were about six months old, about four months after flowering has occurred, these changes were observed. The color of the shell changed from green to rich gold. When the fruit was golden half way up, it could be picked and eaten. The color change of the shell occurred first at the bottom of the fruit and moved upwards. During this change, the fruit became sweeter and the color of the flesh changed from white to yellow.Keywords: Pineapple, Ananas comosus L., flowering, fruiting, growthAfrican Journal of Biotechnology Vol. 12(15), pp. 1774-178

Molecular and genome size analyses of somaclonal variation in apple rootstocks Malling 7 and Malling 9

The cultivated apple (Malus domestica) is important fruit crops cultivated in world. For production and breeding of high quality apple, inducing and enhancing new genetic diversity and suitable traits are necessary. In Iran, different local and imported apple genotypes are cultivated and common apple root stocks (Malling 7) M7 and (Malling 9) M9 are mostly used root stocks in the country. Therefore, we studied genetic diversity of M7 an M9 tissue culture regenerated plants produced by different treatments by using twenty ISSR markers. In total 51 randomly selected plants were studied for the occurrence of somaclonal variation in apple mother plants and tissue culture regenerated plants. Four different treatments were used for tissue culture. Genetic diversity parameters, genetic distance and polymorphism percentage were studied in regenerated plants. Variations in loci frequency and combination were checked by STRUCTURE and the presence of similar loci in the plants was studied by reticulation NJ tree. Genetic relationship versus distinctness was determined by principal coordinate analysis. The results showed the occurrence of genetic variation among mother plants and tissue culture regenerated plants of each subculture due to somaclonal variation. Significant difference in the genome size among some of the regenerated plants indicates that change in genetic structure of plants during tissue culture is also accompanied with quantitative change in DNA. However, degree of genetic variation differed among apple rootstocks and also among different treatments used

Evaluation of antioxidant and cytoprotective activities of Artemisia ciniformis extracts on PC12 cells

Objective(s): In the current study antioxidant capacities of five different extracts of Artemisia ciniformis aerial parts were evaluated by cell-free methods. Then seven fractions of the potent extract were selected and their antioxidant capacity was assayed by cell free and cell based methods. Materials andMethods: Antioxidant ability was measured using the: 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging test, β-carotene bleaching (BCB) method and ferrous ion chelating (FIC) assay. Total phenolic contents (TPC) of all the samples also were determined. The cytoprotective effect of fractions was evaluated by measuring the viability of cells after exposure to doxorubicin (DOX). The mechanism of action was studied by investigating caspase-3, mitochondrial membrane potential (MMP), the level of super-oxide dismutase (SOD) and intracellular reactive oxygen species (ROS). Results: Hydroethanolic extract exhibited a notably higher antioxidant activity and phenolic content. Among the fractions (A to G) of hydroethanolic extract, the highest antioxidant capacity was observed in the Fraction E. Moreover, 24 hr pretreatment of PC12 cells with fractions B, C and D decreased DOX-induced cytotoxicity. In addition, pre-treatment of cells with fraction B resulted in significant decrease in generation of the reactive oxygen species (ROS) and increase in the activity of SOD. We were able to demonstrate remarkable reduction in the activity of caspase-3 and increase in MMP in PC12 cells following pretreatment with fraction B. Conclusion: Our observations indicated that the fraction B of A. ciniformis hydroetanolic extract possessed protective effect on oxidative stress and apoptosis induced by DOX in PC12 cells

Simple sequence repeat (SSR) and inter simple sequence repeat (ISSR) analyses of genetic diversity in tissue culture regenerated plants of cotton

Cotton is one of the main economic crop plants of Iran cultivated under continuous artificial selection and cultivation which may lead to genetic erosion and possible loss of useful genetic loci resulting in vulnerability to pests and diseases. For this reason increasing and improving the amount of genetic diversity in cotton germplasm through tissue culture is important. The present report considers genetic diversity induced in tissue culture regenerated plants of three cotton cultivars namely Mehr, Sindose and their hybrid Mehr X Sindose. Surface of seeds were disinfected with 70% ethanol for 2 min and then treated with 5% hypochlorite solution for 20 min. Finally, they were washed 3 to 4 times with sterile distilled water and inoculated aseptically on Murashige and Skoog (MS) basal medium free hormones. Single nodes resulted from seedlings cultured as explants. Inter simple sequence repeat (ISSR) and simple sequence repeat (SSR) primers used produced different number of bands in the genotypes studied showing different levels of molecular polymorphisms in each cultivar. Some common and few specific ISSR/SSR loci were indentified while some bands were present in all the genotypes except one indicating genetic changes in them. Analysis of molecular variance (AMOVA) test showed significant difference (p < 0.05) for ISSR markers but not for SSR markers. Molecular trees obtained showed genetic variations among the regenerated plants of each cultivar due to tissue culture.Keywords: Cotton, genetic diversity, ISSR, RAP

A Review of Current Methodologies for Regional Evapotranspiration Estimation from Remotely Sensed Data

An overview of the commonly applied evapotranspiration (ET) models using remotely sensed data is given to provide insight into the estimation of ET on a regional scale from satellite data. Generally, these models vary greatly in inputs, main assumptions and accuracy of results, etc. Besides the generally used remotely sensed multi-spectral data from visible to thermal infrared bands, most remotely sensed ET models, from simplified equations models to the more complex physically based two-source energy balance models, must rely to a certain degree on ground-based auxiliary measurements in order to derive the turbulent heat fluxes on a regional scale. We discuss the main inputs, assumptions, theories, advantages and drawbacks of each model. Moreover, approaches to the extrapolation of instantaneous ET to the daily values are also briefly presented. In the final part, both associated problems and future trends regarding these remotely sensed ET models were analyzed to objectively show the limitations and promising aspects of the estimation of regional ET based on remotely sensed data and ground-based measurements

Comparison of liquid culture methods and effect of temporary immersion bioreactor on growth and multiplication of banana (Musa, cv. Dwarf Cavendish)

Four different liquids, as well as solid culture methods used in shoot propagation of banana were compared. Treatments studied were solid medium (A), liquid medium with immersion of plants (B), liquid medium with cotton culture support (C), liquid medium aerated by bubbling (D), and liquid medium with a temporary immersion bioreactor system (TIB) for 20 min every 1 h (E). After 4 weeks of culture, shoots in liquid medium with immersion and liquid medium aerated by bubbling showed none too little proliferation. Shoots in the solid medium and those cultured in liquid medium containing cotton culture supported played multiplication rates of 2.7 to 3.5 with the highest multiplication rate (> 7.00) observed in the explants that were subjected to the TIB in the medium. Three treated groups differed in the accumulation of dry matter; the lowest weight (around 0.6 g) was observed in treatments B and D, while 2 to 4 times greater accumulation was observed in the explants in the solid medium and those cultured in the liquid medium with a cotton culture support. The highest multiplication rates and weight gains were observed in the liquid medium with a TIB (E). Shoots in liquid medium continuously aerated by bubbling, displayed hyperhydricity of the outer leaf sheaths. However, this was not observed with temporary immersion of explants.Keywords: Banana, micropropagation, dwarf cavendish, temporary immersion bioreactor (TIB

Somaclonal variation of tissue culture regenerated plants of Aloe barbadensis Mill.

Aloe barbadensis is perennial, monocotyledonous, fleshy plant belongs to Aloaceae family. In this study, somoclonal variations of regenerated A. barbadensis plants were investigated. The plantlets of forth subculture transferred to the soil for further study. The genomic DNAs of 40 regenerated plantlets were extracted and genetic variations were studied using SPAR markers including RAPD and ISSR primers. The amounts of Aloe gel also were extracted from regenerated A. vera plants. Average percentage of polymorphism, Shannon index, Nei's genetic diversity and number of effective alleles based on RAPD data were higher than genetic parameters obtained from ISSR data. NJ cluster and STRUCTURE plot based on molecular markers grouped regenerated plants to distinct clusters. AMOVA analysis also showed a significant (P = 0.01) genetic distinction between studied groups. This result also confirmed differentiation of regenerated plants. The amount of Aloe gel in the four groups (based on clustering method) was compared by using analysis of variance (ANOVA). The results showed no significant (P = 0.746) differences between the amount of gel in four group. In total, our findings showed somaclonal variations on genomic level while no significant differences were observed in amount of gel among regenerated Aloe plantlets

Genetic finger printing of cotton cultivars by ISSR molecular markers

Gossypium hirsutum is one of the main tetraploid cotton species that is cultivated throughout the world. Due to continuous selection of cotton cultivars for specific agronomic traits, the genetic variability within the cultivars decrease that lead to genetic erosion. To tackle the problem of reduced genetic variability, we should track all available genetic diversity within cotton germplasm and use them for inter-specific and intra-specific hybridization and produce new elite cotton cultivars. Therefore, the present study used ISSR molecular markers to illustrate genetic variability in 13 tetraploid cotton genotypes (Gossypium hirsutum L.) and to categorize these genotypes based on genetic affinity. 65 cotton plants were studied. The results identified private bands in the studied genotypes, while Network and STRUCTURE analyses of molecular data obtained grouped the genotypes with genetic affinity together. Some of the genotypes differed in their genetic content from the others; therefore, studying the genetic and agronomic variability within available cultivars is very important and produced data to broaden the gene pool for planning further hybridization in cotton

Genetic structure of cultivated flax (Linum usitatissimum L.) based on retrotransposon-based markers

Flax (Linum usitatissimum L.) is one of the most important fiber and oil crop plants cultivated since ancient time. The flax seeds contain high amount of omega- 3-fatty acids and biologically active lignans. In spite of economic importance of cultivated flax, no information is available on its genetic variability and population structure in Iran. Therefore, we used six inter-retrotransposon amplified polymorphism (IRAP) markers and 15 combined IRAP markers to reveal within and among population genetic diversity in this crop plant. We used 30 randomly selected plants in three geographical populations for present investigation. AMOVA test produced significant genetic difference (PhiPT = 0.40, P = 0.010) among the studied populations and also revealed that, 40% of total genetic variability was due to within population diversity while, 60% was due to among population genetic differentiation. Gst (0.78, P = 0.001), Hedrick, standardised fixation index (G'st = 0.83, P = 0.001), revealed that the studied populations are genetically differentiated. STRUCTURE plot based on admixture model revealed that the studied populations differed extensively in their genetic content, but some degree of shared alleles occurred between them. Some adaptive IRAP loci were identified by LFMM analysis. These loci were private alleles restricted to geographical populations. Data obtained may be used in breeding and hybridization program of flax in the country