Application of membrane separation processes in petrochemical industry: a review

Doubled Haploid Production in Crop Plants

Worldwide interest in oligosaccharides has been increasing ever since they were accorded the prebiotic status. The oligosaccharides of various origin like, bacteria, algae, fungi and higher plants have been used extensively both as food ingredients and pharmacological supplements. The non-digestible oligosaccharides have been implicated as dietary fibre, sweetener, weight controlling agent and humectant in confectioneries, bakeries and breweries. Functional oligosaccharides have been found effective in gastrointestinal normal flora proliferation and pathogen suppression, dental caries prevention, enhancement of immunity, facilitation of mineral absorption, source of antioxidant, antibiotic alternative, regulators of blood glucose in diabetics and serum lipids in hyperlipidemics. Apart from the pharmacological applications, oligosaccharides have found use in drug delivery, cosmetics, animal and fishery feed, agriculture, etc. Keeping in view the importance of the functional oligosaccharides, we present an overview of their natural sources, types, structures, physiological properties. Conventional as well as novel synthesis, purification and analysis methods are summarized. Recent promising developments in this area are presented to facilitate their further exploitation.

Functional oligosaccharides: production, properties and applications

Plant breeding is focused on continuously increasing crop production to meet the needs of an ever-growing world population, improving food quality to ensure a long and healthy life and address the problems of global warming and environment pollution, together with the challenges of developing novel sources of biofuels. The breeders' search for novel genetic combinations, with which to select plants with improved traits to satisfy both farmers and consumers, is endless. About half of the dramatic increase in crop yield obtained in the second half of the last century has been achieved thanks to the results of genetic improvement, while the residual advance has been due to the enhanced management techniques (pest and disease control, fertilization, and irrigation). Biotechnologies provide powerful tools for plant breeding, and among these ones, tissue culture, particularly haploid and doubled haploid technology, can effectively help to select superior plants. In fact, haploids (Hs), which are plants with gametophytic chromosome number, and doubled haploids (DHs), which are haploids that have undergone chromosome duplication, represent a particularly attractive biotechnological method to accelerate plant breeding. Currently, haploid technology, making possible through gametic embryogenesis the single-step development of complete homozygous lines from heterozygous parents, has already had a huge impact on agricultural systems of many agronomically important crops, representing an integral part in their improvement programmes. The aim of this review was to provide some background, recent advances, and future prospective on the employment of haploid technology through gametic embryogenesis as a powerful tool to support plant breeding.

Gametic embryogenesis and haploid technology as valuable support to plant breeding

Lactulose: production, purification and potential applications.

Isomerization of lactose to lactulose study and comparison of three catalytic systems

Emulsion liquid membrane pertraction of L-lysine from dilute aqueous solutions by D2EHPA mobile carrier

Pollen microspores from a hybrid between Lolium multiflorum (2n=4x=28) and Festuca arundinacea (2n=6x=42) were cultured and over 200 androgenic green plants established. In the initial hybrid one chromosome from each of the five homoeologous groups was labelled by a distinct PGI/2 homoeoallele. Segregation of PGI/2 alleles in the male gametes and in the androgenic plants indicated chromosome pairing preferences in the hybrid at meiosis. The pentaploid Festulolium hybrid genome comprised two homologous sets of Lolium (Lm) chromosomes and the polyhaploid set of F. arundinacea, namely one genome of F. pratensis (Fp) and two of F. glaucescens(Fg and Fg1). There was a high degree of preferential chromosome pairing between the two homologous sets of L. multiflorum chromosomes, and each androgenic plant contained a Lolium PGI/2 allele. Results supported earlier work indicating that gamete viability depended on the presence of a complete Lolium genome. Genomic in situ hybridization (GISH) was carried out on mitotic chromosome preparations of two androgenic plants using the total genomic DNA of L. multiflorum as a probe. Recombinants were observed between chromosomes of all three genomes in the pentaploid hybrid, demonstrating the efficacy of the hybrid as a starting point in introgression breeding programmes.

/pdf/interspecific-genomic-rearrangements-in-androgenic-plants-30j0y5kokx.pdf

Interspecific genomic rearrangements in androgenic plants derived from a Lolium multiflorum×Festuca arundinacea (2n=5x=35) hybrid

The pentaploid hybrid of Lolium multiflorum and Festuca arundinacea (2n = 5x = 35) combines the high growth rate of L. multiforum with the drought resistance and freezing-tolerance of F. arundinacea. Unfortunately, it also displays the deleterious traits associated with Festuca, namely those associated with high leaf fibre content giving rise to poor palatability and digestibility. To access different combinations of these characters, anther cultures were initiated and regenerated into single embryo derived plants. The anther culture method was very productive since out of a total of 2349 androgenic plants derived from the same parent plant, 57% were green plantlets, although only 507 (22%) subsequently established into plants following transfer to soil. Chromosome counts of randomly selected lines showed that plants with euploid chromosome numbers (14, 21, and 28) would appear to have selective advantage during regeneration. There was wide variation between mature androgenic plants grown under field conditions in plant height, leaf length, leaf width, tiller number and herbage dry matter. The variation between genotypes in response to drought stress was assessed by placing replicate clones under rain-out shelters or under irrigated control conditions in the field. Herbage dry matter under drought was higher in a number of androgenic lines than either parents, but not higher than the pentaploid hybrid. Androgenesis was shown to be a highly effective procedure to expose diverse phenotypic variation all derived from the same Lolium × Festuca hybrid genotype.

Androgenesis in a Lolium multiflorum X Festuca arundinacea hybrid to generate genotypic variation for drought resistance

New opportunities for plant breeding using androgenesis in Lolium × Festuca hybrids have been identified. Plants derived by anther culture from a Lolium multiflorum × Festuca arundinacea (5x) hybrid were screened for freezing-tolerance, and their post-freezing recovery compared. The androgenic population showed extreme diversity in freezing-tolerance. While the majority of androgenic plants had inferior freezing-tolerance compared with the freezing-sensitive L. multiflorum parent, 6% of the population were more freezing resistant than the freezing-tolerant Festuca parent. Novel Lolium and Festuca gene combinations resulting from rare meiotic events were recovered within the androgenic population. The two most freezing-tolerant androgenic plants carried virtually the entire F. pratensis subgenome of F. arundinacea. F. pratensis is known to carry genes for freezing-tolerance and would be expected to be the primary source of genes governing this trait within the F. arundinacea genome. The most freezing-tolerant androgenic plants were more freezing-tolerant than the hybrid plant from which they were derived. Consequently, androgenesis was also effective in removing factor(s) reducing the expression of freezing-tolerance within the L. multiflorum × F. arundinacea (5x) hybrid.

Abbas Zare

Papers

Isomerization of lactose to lactulose study and comparison of three catalytic systems

Emulsion liquid membrane pertraction of L-lysine from dilute aqueous solutions by D2EHPA mobile carrier

Interspecific genomic rearrangements in androgenic plants derived from a Lolium multiflorum×Festuca arundinacea (2n=5x=35) hybrid

Androgenesis in a Lolium multiflorum X Festuca arundinacea hybrid to generate genotypic variation for drought resistance

Androgenesis from a Lolium multiflorum × Festuca arundinacea hybrid to generate extreme variation for freezing-tolerance