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.
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.
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.
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.
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.
Maize (Zea mays L.) is one of the most important cereals in Egypt due to its vast grown area, total production and cash value. It is essential for human consumption and livestock. Moreover, it is also used for industrial purposes such as manufacturing starch and cooking oils. Many efforts are devoted nowadays to increase its productivity through genetical improvement. Therefore, increasing the productivity of such crop is the main target of corn breeders. To achieve this target more information is needed for the successful breeding programs such as the relative amount of genetic variance components and their interaction with environment for yield and its components. It is hoped that the results of such study would give such information and help in designing successful breeding programs for improving yield and its components in maize.
Wheat is the most important cereal crop used directly as human consumable commodity by the major portion of world’s population. An adequate staple food supply is the first pre-requisite in any country for social and economic stability. Wheat is the most important grain and a staple food for more than one third of the world’s population. Large number of products and by products are obtained from this king of cereals. F2 populations of seven cross combinations Lasani-2008 ? Iqbal-2000, Lasani-2008 ? 9432, Lasani-2008 ? 9436, Lasani-2008 ? 9444, Iqbal-2000 ? Lasani-2008, Iqbal-2000 ? 9432 and Iqbal-2000 ? 9436 involving cultivars/ lines Lasani-2008, Iqbal-2000, 9432, 9436 and 9444 were studied to determine the heritability and expected genetic advance in order to explore and utilize the hidden genetic potential so that new high yielding and better adapted cultivars can be developed in order cope with the rapidly changing environment and global demand of food with minimum inputs.
Wheat (Triticum aestivum L.) belongs to poaceae family. It is the most important and major consumable food cereal of Pakistan. It is the staple food in some areas of the world. Six F2 populations viz., 9432 ? 9444, 9432 ? Iqbal-2000, 9432 ? Lasani-2008, 9436 ? Iqbal-2000, 9436 ? Lasani-2008 and Iqbal-2000? 9444 involving five varieties/lines Iqbal-2000, Lasani-2008, 9444, 9432 and 9436 were evaluated to estimate heritability and genetic advance for various metric traits. The cross combinations namely 9436 ? Iqbal-2000 and 9436 ? Lasani-2008 and parental varieties/lines namely Iqbal-2000 and 9436 appeared to be most promising. Therefore selection among these crosses and parents for improvement of grain yield per plant would give good results.
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.
In order to explore the breeding potential and variability for the evaluation of new better performing, high yielding varieties with good adaptability, heritability and genetic advance were estimated for the following seven cross of F2 population viz., DN 52 ? Fareed 2006, DN52 ? Sehar 2006, DN 53 ? Chakwal 86, DN 53 ? Fareed 2006, DN 57 ? Chakwal 86, DN 53 ? Sehar 2006, DN 57 ? Sehar 2006. Heritability and genetic advance were was determine for the following characters plant height, flag leaf area, number of tillers per plant, spike length, number of spikelet’s per spike, spike density, number of grains per spike, 1000-grain weight and grain yield per plant.
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.
It is hoped that the present study may help maize breeders to produce new hybrid varieties having higher yielding potential. Molecular techniques are now a valuable tool for achieving advances in genome research and generating considerable interest in predicting hybrid performance. Molecular markers are of great value in genetic research and partially in breeding programs since they reflect the genetic variation among individuals. Various PCR-based marker techniques have recently been successfully introduced in the fingerprinting of plant genomes and in genetic diversity studies. Among them random amplified polymorphic DNA (RAPD) analysis which is relatively simple, rapid and cost effective. Diallel cross design is widely and extensively used for estimating the types of gene action. Several methods have been devised in this respect to estimate the genetic components in plant population, few information, however is available about comparing and relative efficiency of these methods.
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.
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.
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