Bread wheat (Triticum aestivum L. em. Thell) is one of the most important cereal grain crop of the world and is cultivated over a wide range of climatic conditions. For a successful breeding program the inheritance of yield related traits is a pre- requisite. This monograph communicates the inheritance pattern of yield and related traits in bread wheat (Triticum aestivum L.) using 8x8 diallel analyses. Graphical analysis revealed additive gene action for days to heading, days to maturity, plant height, grains per spike, 1000 grains weight and harvest index. While over dominance gene action for flag leaf area, tillers per plant, Spike length and yield per plant. The GCA mean squares were significant for all traits except tiller per plant and yield per plant and were greater than SCA mean squares indicating the preponderance of additive genetic effects. The parents Tkb, Tat, Sarc-3 and SQ- 92 were good general combiners. The parents Tkb , Tat , Sarc-3 and SQ-92 and the specific crosses that showed high mid parent and better parent heterosis are recommended for further use in wheat breeding programmes.
In this manuscript, we have used for the first time two important approaches of genetic dissection (QTL interval mapping and association mapping) together for the study of marker-trait associations for the identification of molecular markers associated with a variety of economically important traits with emphasis on grain weight (GW)in bread wheat. We mainly focused on the following aspects: (i) Preparation of whole-genome framework linkage map of an intervarietal RIL mapping population developed specifically for GW and derived from the cross Chinese Spring ? Rye Selection 111 . (ii) Single-locus QTL analysis (interval mapping) for GW (including other grain traits), and other agronomically important traits using the above RIL mapping population. (iii) Study of QTL ? QTL epistatic interactions and QTL ? environment interactions using two-locus QTL analysis. (iv) Study of genetic diversity and population structure of a collection of elite Indian bread wheat cultivars. (v) Association mapping of GW and other agronomically important traits using above collection of elite Indian bread wheat cultivars.
The book attempted to establish the genetic basis and inheritance of seedling growths traits in Acacia senegal provenances via estimation of the general and specific combining abilities of parents and crosses respectively. It also aimed at determining the extend of heterosis and inter relationship among the measured traits in a 6 x 6 diallel crossing procedure using Griffing’s model 1, method 2.
Human life on earth strongly depends upon a countable number of plant species. Most important food crops that are being utilized in the world are wheat, rice, corn and sorghum. Among them wheat(Triticum aestivum, L) is the most widely grown crop and is highly esteemed in the world. Diallel cross technique is one of the most efficient technique which can provides information to exploit the genetic mechanism and inheritance pattern for manipulation of polygenic traits involved in early generations and are particularly suited to autogamous crops like wheat. Thus this technique enable plant breeder to screen his breeding material in early generations. The present studies are, therefore, initiated with the prime objective to get the comprehensive knowledge about nature of gene action and magnitude of its contribution to various characters in a 5 ? 5 diallel cross. Information derived may be effectively exploited in developing and formulating an efficient breeding program for the evolution of better quality and high yielding varieties.
Pisum sativum L. is of great importance because it is suitable not only for fresh consumption, but it provides considerable raw material for the canning industry. It can be fitted well into the crop rotation; it is eco-friendly, after the pea the soil is enriched with nitrogen. Breeding of peas has been substantial to produce new genotypes with better qualitative and quantitative traits to suffice the demand of the market. In generally the diallel crossing has been used for getting the most completely genetic information about the inheritance of quantitative traits of the genotypes. Combining ability studies were made in F1 generation for four yield-determining quantitative traits: pod per plant, seed per pod, pod length and plant high. F3 generation was genetically characterized and genetic advancement was tracked by evaluations of subsequent generations.
High molecular weight glutenin subunits are the key factors that influence bread making quality of common wheat. A number of HMW glutenin subunits have been detected using SDS-PAGE within each locus i.e. Glu-A1, Glu-B1 and Glu-D1 in common wheat. Particularly, alleles encoding the HMW glutenin subunits are associated with different dough properties of wheat. Of these, the allelic variation at the Glu-D1 locus has a particularly strong effect. Current study was undertaken with the main objective to study and characterize a group of synthetic elite genotypes for their high molecular weight glutenin subunit alleles in order to rank these elites for their bread making quality traits. For this, a total of 45 synthetic elites were picked from the elite set of 95 entries released by CIMMYT.
Wheat is an important cereal crop throughout the world and also in Pakistan. A lot of research work is going on to develop high yielding wheat varieties.Line?tester analysis is one of efficient breeding strategies to evaluate combining ability effects of genotypes and also to provide information regarding genetic mechanisms controlling yield and yield related traits.Combining ability analysis would be of great help to identify the most suitable and desirable parental material to breed further to get the hybrids which have the desirable characters for the breeders.The line x tester cross experiment in spring wheat (Triticum aestivum L.) was used to estimate the combining ability effects involved in the control and expression of some polygenic traits of economic importance.This book provide information regarding wheat and its yield related traits to improve the yield.
Rice is ranked as the world’s number one human food crop and accounts for more than half of the world’s daily calorie intake. It is an economically important food crop that is domesticated after wheat and helps in poverty alleviation. In the present study, 20 advanced lines were evaluated for yield and yield attributing traits and resistance to bacterial blight. For quantitative trait analysis out of 53 traits, 13 agronomic traits, 29 morphological traits and 11 grain quality traits were studied.
The present was carried out on “Genetic analysis of yield component traits in rice. Diallel analysis was carried out based on the method I and model I as suggested by Griffing. Seven economically important yield components traits were evaluated based on per se performance, general and specific combining ability effects, gene action and heterosis. The cross ADT 36 ? ADT 37 and ASD 16 ? ADT 36 exhibited highly significant sca effects and highly significant heterosis for grain yield and for most of its yield component traits. Hence, these crosses can be exploited for heterosis breeding provided cms system is available in the genetic background of ADT 36 and ASD 16 and thereby amidst farming community.
Genetic information, especially about the nature of combining ability and type of gene action governing inheritance of important traits are guidelines to a breeder in selecting parents for development of hybrids, varieties and lines. This book is about results of research conducted on non segregating generations (parents and F1s ) and selected segregating (F2) population derived from 12 elite bread wheat (Triticum aestivum L.) genotypes following line by tester mating system. Parameters such as days to flowering and maturity; plant height, number of tillers per plant; peduncle length; spike length; total biomass per plant; number of grains per spike; grain yield per plant; 100-grain weight; and harvest index were analyzed and moreover, rust resistance mechanism was also considered. The objective is to reveal information on extent of heterosis and inbreeding depression; nature of gene action; extent of variability and genetic advance; association of component traits with each other and grain yield; and the way the component traits affect grain yield and finally rust resistance mechanisms. The book is helpful to mid-level researchers and students who seek to know more about wheat.
Wheat (Triticum aestivum) is king of cereals and it is the staple food of the people of Pakistan. To understand the genetics of drought tolerance two promising elite lines V- 04189 and V-03138 were crossed to develop F1, F2 and back cross generations (BC1 and BC2). Six generations (P1, P2, F1, F2, BC1 and BC2) were raised under water stress conditions. Analysis of variance showed significant difference among generation means which indicated presence of sufficient genetic variability. Hybrid vigor was observed in most of the cases except plant height, spike length and flag leaf area. Generation means analysis revealed presence of additive [d], dominance [h] and epistasis genetic effects in the inheritance of traits. Two parameter model [md] provided the best fit for spike length, number of tillers per plant relative water contents and excised leaf water loss which shows the presence of additive genetic effect is prominent with simple inheritance while, [ml] showed best fit for grain yield per plant that indicates epistasis is involved in the inheritance of trait. The remaining traits exhibited higher parameter models and indicating the complex inheritance.
Various forms of the diallel crosses play an important role in evaluating the breeding potential of genetic material in plant and animal breeding. In this paper we give the simple method of construction of partial diallel cross design through partially balanced incomplete block design as auxiliary design with the method of analysis and also see the importance of partial diallel cross design through partially balanced incomplete block design when large number of inbred line exist in plant and animal breeding experiment. We compare the efficiencies of our proposed designs with other existing designs for partial diallel cross in the literature and found that several our designs have higher A- and D-efficiency in comparison to the existing designs. The result provides a new partial diallel cross designs for plant and animal breeding experiments.
Wheat is one of the most important domesticated crops grown around the world. Wheat seed storage proteins represent an important source of energy in wheat, being involved in determination of bread making quality. Seed storage proteins are traditionally classified as gliadins and glutenins. Glutenins are divided into low molecular weight glutenin subunits (LMW-GS), 30-50KDa and high molecular weight glutenin subunits (HMW-GS), 80-120KDa. HMW-GSs are encoded at genes Glu-A1, Glu-B1 and Glu-D1. Although HMW-GSs only occupy around 10% of wheat seed storage proteins, they play a major role in bread making quality. A single hexaploid variety could contain 6 HMW-GSs. Protein profiling is the most effective tool for studying the genetic diversity of HMW-GS in wheat varieties.The objective of this study was to perform the protein profiling of wheat HMW-GSs of 21 Pakistan’s wheat varieties. Different allelic combinations of Glu-1 loci were identified. At Glu-A1 locus,2*, at Glu-B1 locus,17+18 and 7+8 and Glu-D1 locus,2+12 alleles were dominant in 21 experimental wheat varieties.
This book wrote primarily aimed to understand the inheritance of terminal heat tolerance in bread wheat (Triticum aestivum L. em.Thell). I hope the findings embodied in the work would be of immense value to wheat breeders and geneticists alike in enhancing wheat productivity in heat stress regions of the world and of the country in particular. Terminal heat caused by high temperatures during kernel development has emerged as a major threat to wheat production globally and has become priority number one in wheat breeding programme in view of global warming, forced to breed for terminal heat tolerant varieties having good tolerance against heat stress. In this endeavour genotypes/ germplasm/wild sources of heat tolerance should be identified and its inheritance work out for utilization in wheat breeding programs to enhance its productivity to meet the ever increasing demand of wheat to feed the growing population. DEDICATED TO MY BELOVED PARENTS
Plant breeders are always on a hunt for appraising the nature of rice varieties when put in cross combination so that they can have useful plant types in segregating generations following hybridization. This could best be accomplished when one knows the combining ability (both general and specific), heterotic effect, and type of gene action of the parents for different traits. In this study, 10 rice varieties were crossed in a diallel fashion (excluding reciprocals). The data for the parents and 45 crosses were statistically analyzed and good general and specific combiners were sorted out. The analysis of heterosis showed which parents produced heterotic hybrids. The type of gene action for the parents is discussed separately.