Plant Breeding Methods Research Articles

Development and characteristics of ω-gliadin-free wheat genotypes

AbstractOmega gliadin proteins are one of the most allergenic components of wheat gluten. Proteins of the ω-5 subgroup are recognized as main allergens causing wheat dependent exercise induced anaphylaxis—the most dangerous, life-threatening IgE mediated food allergy. A set of wheat genotypes lacking all ω-gliadins has been developed by cumulating inactive gene variants in three gliadin coding loci (Gli A1, Gli B1 and Gli D1), using traditional plant breeding methods. Endosperm proteins of ω-gliadin-free genotypes were compared to a control genotype containing all ω-gliadins by A-PAGE, SDS-PAGE and RP-HPLC. A considerable decrease (about 30 %) of gliadin immunoreactivity as a consequence of ω-gliadin elimination was demonstrated by ELISA, using sera of ten patients allergic to gluten. Preliminary evaluation of the technological properties of the ω-gliadin-free genotype by the SDS sedimentation test suggests that elimination of all ω-gliadins may also significantly improve wheat bread making quality.

English

The history of mutations with early results in soybean has been well documented in the literature available. Mutation breeding has been used in recent years as a valuable supplement to other methods of plant breeding in generating new variability and development of crop varieties with new architecture, superior biochemical constitution and suitable growth and developmental rhythms. The utility of this method is evident from the fact that in several crops induced mutants have been released as new varieties. In this paper, efforts have been made to review the literature on induced mutations in soybean. The different mutagenic agents used for inducing mutations, effects of different mutagenic agents on yield, quality contributing characters and resistance to different diseases have been described. Key words: Glycine max (L.) Merrill, induced mutagenesis, crop varieties.

Effect of cyanobacterial extracellular products on high-frequency in vitro induction and elongation of Gossypium hirsutum L organs through shoot apex explants

Abstract The challenging task of bringing high efficiency transformed plants attracts lot of attention in recent times. In search for this, there have been many attempts made using, different techniques like tissue culture and plant breeding methods. Here we report a suitable alternative facile route, where cyanobacterial extracellular products are utilized as growth regulators and its performance validated on Gossypium hirsutum L. MS medium is tested with cyanobacterial extracellular products of Nostoc ellipsosporum, Dolichospermum flos-aquae and Oscillatoria acuminata .Our best results show that the addition of O. acuminata extracellular product with plant growth hormones gives the excellent induction and elongation in cotton. In addition to this, the multiple shoot was obtained on MS medium fortified with 1.0 mg L −1 BA with 8% O. acuminata and 1.5 mg L −1 TDZ with 12% O. acuminata . High frequency of shoot elongation supplemented with MS medium, iP 2.5 mg L −1 and 16% O. acuminata and root production MS medium fortified with 12% O. acuminata best responsible for regeneration in cotton plants. The rooted plants were hardened and transferred to soil with 90% survival rate.

Plant High-Affinity Potassium (HKT) Transporters Involved in Salinity Tolerance: Structural Insights to Probe Differences in Ion Selectivity

High-affinity Potassium Transporters (HKTs) belong to an important class of integral membrane proteins (IMPs) that facilitate cation transport across the plasma membranes of plant cells. Some members of the HKT protein family have been shown to be critical for salinity tolerance in commercially important crop species, particularly in grains, through exclusion of Na+ ions from sensitive shoot tissues in plants. However, given the number of different HKT proteins expressed in plants, it is likely that different members of this protein family perform in a range of functions. Plant breeders and biotechnologists have attempted to manipulate HKT gene expression through genetic engineering and more conventional plant breeding methods to improve the salinity tolerance of commercially important crop plants. Successful manipulation of a biological trait is more likely to be effective after a thorough understanding of how the trait, genes and proteins are interconnected at the whole plant level. This article examines the current structural and functional knowledge relating to plant HKTs and how their structural features may explain their transport selectivity. We also highlight specific areas where new knowledge of plant HKT transporters is needed. Our goal is to present how knowledge of the structure of HKT proteins is helpful in understanding their function and how this understanding can be an invaluable experimental tool. As such, we assert that accurate structural information of plant IMPs will greatly inform functional studies and will lead to a deeper understanding of plant nutrition, signalling and stress tolerance, all of which represent factors that can be manipulated to improve agricultural productivity.

Traditional and Modern Plant Breeding Methods with Examples in Rice (Oryza sativa L.)

Plant breeding can be broadly defined as alterations caused in plants as a result of their use by humans, ranging from unintentional changes resulting from the advent of agriculture to the application of molecular tools for precision breeding. The vast diversity of breeding methods can be simplified into three categories: (i) plant breeding based on observed variation by selection of plants based on natural variants appearing in nature or within traditional varieties; (ii) plant breeding based on controlled mating by selection of plants presenting recombination of desirable genes from different parents; and (iii) plant breeding based on monitored recombination by selection of specific genes or marker profiles, using molecular tools for tracking within-genome variation. The continuous application of traditional breeding methods in a given species could lead to the narrowing of the gene pool from which cultivars are drawn, rendering crops vulnerable to biotic and abiotic stresses and hampering future progress. Several methods have been devised for introducing exotic variation into elite germplasm without undesirable effects. Cases in rice are given to illustrate the potential and limitations of different breeding approaches.

Null Alleles in Gliadin Coding Loci and Wheat Allergenic Properties

Wheat gliadin proteins-an important, nutritional component of many food products may also act as allergenic proteins causing various, clinical symptoms of IgE-mediated food allergies. Gliadins are coded by six complex loci on the chromosomes 1A, 1B, 1D,6A, 6B and 6D of wheat genome. Each of the loci coding from a few to a dozen of polypeptides may spontaneously mutate to inactive gene variants called null alleles that do not code any proteins at all. The aim of the present work was to find out whether null alleles in some gliadin coding loci may decrease wheat allergenic properties. Six winter wheat genotypes: gliadin deletion lines (GDL) containing null alleles on 1D, 1B and 6B chromosomes and control lines (CL) containing active gene variants in all gliadin coding loci, were developed using plant breeding methods. Allergenic properties of the six analyzed hybrids were estimated by ELISA using polled sera of five patients allergic to gluten. Estimated immunoreactivity of GDLs was from 6% to 18% lower as compared with CLs. The obtained results evidenced that gliadin null alleles decrease wheat allergenic properties and may be used as parental forms for breeding of hypoallergenic wheat genotypes.

An Empirical Approach to Get the Vitality of a Genotype to Water Stress Tolerance in Yield and Yield Contributing Traits

Conventional methods of plant breeding and agronomic practices remained a successful tool to maintain the pace of food production for centuries but due to changing climatic conditions and the challenges of 21st century like population growth, pollution, declining biodiversity and food security have shaken the previous policies. This situation compelled the agriculturist towards the judicious management of natural resources to combat the poverty, disasters and increased food demands. The present study was initiated to check wheat varieties in two water provision conditions. The results revealed that environmental stresses played negative role by minimizing the yield and yield contributing traits. However the severity of water stress was depleted by some promising genotypes by showing minimum hazard effects and by having capability to contribute to conserving biodiversity, ensuring sustainability, combating food insecurity and increasing economic benefits. The minimum effect of moisture stress on grain yield was shown by genotypes C-518 (12.97%) while the genotype Shakar, Pari-73 and Uqab-2000 showed maximum decline percentage. The global warming and population explosion will further induce commodity shortage and law and order situation in the world. The prevailing International tension can be cooled down by the provision of marshal aids by the developed countries to the effected or threatened countries.

Morphological divergence among progeny of Macroptilium lathyroides accessions from the semi-arid region of Pernambuco, Brazil

Macroptilium is a legume genus with approximately 20 species, usually annual or biennial, herbaceous and distributed mainly in the Americas. It is widely used as a forage resource in grasslands and usually fixes atmospheric N. Martins et al. (2001) indicated that half-sib family selection with progeny testing is the most common plant breeding method used in Brazil. In the scientific literature, however, there are few studies dedicated to Macroptilium spp. This study evaluated morphological divergence among Macroptilium spp. progeny from accessions collected in 4 counties located in the semi-arid region of Pernambuco State, NE Brazil.

Distance Learning for Pepper and Corn Breeding and Seed Production

The one-year vocational education in seed breeding and production technology (SBP) at Padjadjaran University provide an opportunity for seed professionals to produce pepper and corn seed. Nowadays most of food-crop farmers in Indonesia grow pepper and corn by using, mainly, imported seed. The production of local pepper and corn seed reached only 10% and 35,86% of national need. The purpose of SBP program i s to provide breeders which have general knowledge and practice in pepper and corn seed production. The emphasis of this education method is distance learning for develop students knowledge in simple method of plant breeding, plant variety protection, registration of plant variety for seed distribution and seed certification. However, improving practical knowledge by distance learning will not guarantee the effectiveness of the program to deliver qualified breeder and seed producer. Laboratory, green house as well as field works should be performed so that students will have sufficient understanding and experience as breeder and seed producer when they work in seed company or they found their own company. To support this hybrid vocational education program, lectures from University attend and monitor student work regularly.

Patenting of Plant Varieties and Plant Breeding Methods

This article considers the relationship between patenting and plant variety rights protection, through a detailed analysis of the recent determination by the Extended Board of Appeal of the European Patent Office that methods for breeding broccoli and tomatoes were not patentable. It concludes that the right to patent agricultural innovations is increasingly located within a political context.

ENHANCEMENT OF THE GENETIC DIVERSITY IN PELARGONIUM (SECTION PELARGONIUM) BY SPECIES INTROGRESSION

Beside today’s most important Pelargonium cultivars in the groups of Zonal and Ivy Pelargoniums, Regal Pelargoniums (P. ×domesticum L.H. Bailey) and Pelargonium crispum hybrids are attractive ornamental plants with long breeding histories, too. Here, the pedigrees trace back to crosses with only a few species accessions. Despite numerous cultivars, there is only a low level of genetic and phenotypic variation which is experienced in current breeding programs. Thus, modern cultivars of both groups are examples for a funnel effect. The genus Pelargonium offers with over 250 wild species in 16 sections a large genetic diversity. Numerous wild species of the section Pelargonium are characterized by entire different traits in comparison to the common cultivars such as flower traits, habitus or demands on growing conditions. The domestication of these species failed, among others, because of crossing barriers like different ploidy levels and the availability of these resources for cross-combination. Classical and modern methods of plant breeding can make these species available for the application-oriented plant breeding. Preliminary results of interspecific hybridization between species of the section Pelargonium are presented including pollination studies, genetic and molecular investigations.

Genome-enabled prediction of genetic values using radial basis function neural networks.

The availability of high density panels of molecular markers has prompted the adoption of genomic selection (GS) methods in animal and plant breeding. In GS, parametric, semi-parametric and non-parametric regressions models are used for predicting quantitative traits. This article shows how to use neural networks with radial basis functions (RBFs) for prediction with dense molecular markers. We illustrate the use of the linear Bayesian LASSO regression model and of two non-linear regression models, reproducing kernel Hilbert spaces (RKHS) regression and radial basis function neural networks (RBFNN) on simulated data and real maize lines genotyped with 55,000 markers and evaluated for several trait–environment combinations. The empirical results of this study indicated that the three models showed similar overall prediction accuracy, with a slight and consistent superiority of RKHS and RBFNN over the additive Bayesian LASSO model. Results from the simulated data indicate that RKHS and RBFNN models captured epistatic effects; however, adding non-signal (redundant) predictors (interaction between markers) can adversely affect the predictive accuracy of the non-linear regression models.

New Technologies, Tools and Approaches for Improving Crop Breeding

New Technologies, Tools and Approaches for Improving Crop Breeding

Patenting of plant varieties and plant breeding methods

This article considers the relationship between patenting and plant variety rights protection, through a detailed analysis of the recent determination by the Extended Board of Appeal of the European Patent Office that methods for breeding broccoli and tomatoes were not patentable. It concludes that the right to patent agricultural innovations is increasingly located within a political context.

Genetic variability, heritability and trait associations in durum wheat (Triticum turgidum L. var. durum) genotypes

Information on the extent of genetic variability and heritability as well as correlation among agronomically important traits is a requirement to design a suitable plant breeding method. The present research was conducted at Sinana, Southeastern Ethiopia during the 2009 main crop growing season. The experimental material consisted of 16 durum wheat genotypes tested in a randomized complete block design with three replications. Twelve agronomic traits were included in the investigation. Highly significant differences were revealed among durum wheat genotypes for all traits studied, suggesting the possibility of improving durum wheat for these traits. Plant height and number of kernels per spike showed the highest phenotypic and genotypic coefficients of variations and genetic advance, whereas, days to maturity and test weight had the lowest values. Plant height exhibited highest heritability value of 98.3% while number of spikelets per spike showed minimum value of 36.4%. The genotypic correlations estimated showed positive association of grain yield with days for heading (r=0.50), harvest index (r=0.69) and kernels number per spike (r=0.81). Harvest index (1.13) and biomass (0.81) exhibited the highest positive and significant direct effect on grain yield. Hence, these traits could be considered as suitable selection criteria for the development of high yielding durum wheat varieties. Key words: Correlation coefficient, durum wheat, genetic advance, heritability, path coefficient.

Evolution of plant breeding

Plant breeding is considered one of the longest ongoing activities undertaken by humans, who select plants more productive and useful to themselves and the animals for at least 10,000 years ago. The evolution of civilizations paralleled the success of plant breeding, although this has not been recognized by the public. The reason may be lack of understanding of what plant breeding encompasses. The concept of plant breeding evolved, depending on the time it was formulated, but without losing the essence of being art and science of manipulating plants for man. This review discusses the evolution of the concepts and the methods of plant breeding, here divided arbitrarily into selection based on phenotypes, breeding values and genotypes. No matter how big the pool of genetic information in recent years, the phenotype will continues to be important in the present and future.

Patents and Plant Breeding: Implications for Food Security

This article examines the inter-relationship between plant variety protection (PVP) laws and patent laws and their implications for food security. PVP laws were developed to encourage and protect agricultural innovations by conferring exclusive rights upon the developers of new plant varieties, subject to exceptions for farmers to save seeds for future plantings and for plant breeders to develop new varieties. With the application of recombinant DNA technologies to agriculture and the possibility of patenting DNA and associated enabling technologies the seed saving privilege and breeders’ exception in PVP laws could be circumvented. This has important implications for food security, as does recent efforts of plant breeders to patent their breeding methods. This article examines two recent determinations by the European Patent Office’s Enlarged Board of Appeal concerning attempts to patent plant breeding methods.

In silicocomparative analysis of SSR markers in plants

BackgroundThe adverse environmental conditions impose extreme limitation to growth and plant development, restricting the genetic potential and reflecting on plant yield losses. The progress obtained by classic plant breeding methods aiming at increasing abiotic stress tolerances have not been enough to cope with increasing food demands. New target genes need to be identified to reach this goal, which requires extensive studies of the related biological mechanisms. Comparative analyses in ancestral plant groups can help to elucidate yet unclear biological processes.ResultsIn this study, we surveyed the occurrence patterns of expressed sequence tag-derived microsatellite markers for model plants. A total of 13,133 SSR markers were discovered using the SSRLocator software in non-redundant EST databases made for all eleven species chosen for this study. The dimer motifs are more frequent in lower plant species, such as green algae and mosses, and the trimer motifs are more frequent for the majority of higher plant groups, such as monocots and dicots. With this in silico study we confirm several microsatellite plant survey results made with available bioinformatics tools.ConclusionsThe comparative studies of EST-SSR markers among all plant lineages is well suited for plant evolution studies as well as for future studies of transferability of molecular markers.

Methods of plant breeding in the genome era

Methods of genomic value prediction are reviewed. The majority of the methods are related to mixed model methodology, either explicitly or implicitly, by treating systematic environmental effects as fixed and quantitative trait locus (QTL) effects as random. Six different methods are reviewed, including least squares (LS), ridge regression, Bayesian shrinkage, least absolute shrinkage and selection operator (Lasso), empirical Bayes and partial least squares (PLS). The LS and PLS methods are non-Bayesian because they do not require probability distributions for the data. The PLS method is introduced as a special dimension reduction scheme to handle high-density marker information. Theory and methods of cross-validation are described. The leave-one-out cross-validation approach is recommended for model validation. A working example is used to demonstrate the utility of genome selection (GS) in barley. The data set contained 150 double haploid lines and 495 DNA markers covering the entire barley genome, with an average marker interval of 2·23 cM. Eight quantitative traits were included in the analysis. GS using the empirical Bayesian method showed high predictability of the markers for all eight traits with a mean accuracy of prediction of 0·70. With traditional marker-assisted selection (MAS), the average accuracy of prediction was 0·59, giving an average gain of GS over MAS of 0·11. This study provided strong evidence that GS using marker information alone can be an efficient tool for plant breeding.

栄養繁殖植物における突然変異の誘発と育種方法 (第11回太平洋学術会議養蚕部会記事〔英文〕)

栄養繁殖植物における突然変異の誘発と育種方法 (第11回太平洋学術会議養蚕部会記事〔英文〕)