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M. Sc. Dissertations

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20093
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Subject: Genetics × End date: 2009 × Start date: 2009 ×
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    ThesisItemOpen Access
    Assessment of genetic diversity in a collection of red rices
    (CCSHAU, 2009) Chaudhry, Narender; Ahuja, Uma
    Rice (Oryza sativa L.) is one of the important world’s cereal crops, providing staple food for nearly one-half of the global population. It is the only cereal where weedy, wild and cultivated forms are found. In traditional rice growing areas of Asia, in addition to white, rices of red, purple, black, brown, yellow and green colors are known and grown. Rices with red bran layer are called red rices. Some of the wild, cultivated and most of the weedy rices are red. ix Wild species of Oryza are an important source of useful genes. Red rice varieties have tolerance towards stress environments and resistance against important pest, diseases and storage pests. Off type plants having red seeds are considered as weedy although a few of them are colorless. This form of rice is found mixed into cultivated rice fields and shares traits common in both cultivated and wild rice.These are termed ‘Fat beggars’ as they accept what is offered and thrive. These are most difficult to eradicate. They cross with cultivated varieties and produce herbicide tolerant progeny. These have been studied for understanding the evolution of rice and as germplasm tolerant to adverse conditions for rice breeding. At present no cultivated red or wild variety is reported from Haryana though weedy rices are found throughout the state. There is no information available on weedy rice except eradication in Haryana. A collection of cultivated, weedy and wild rices were evaluated for variability at morphological and molecular level.Collection of weedy rices showed significant variability at morphological and molecular level and shared many traits with wild, cultivated white and red rices. Some of weedy rices can be further evaluated for important traits. Diversity at morphological level did not coincide with diversity at molecular level as compared by Euclidean square and UPGMA cluster analysis. 9 primers could be of significance in identification of red rices.One primer i.e Pr836 was found to be unique to weedy rices and giving unique bands in W8 which is long grain like basmati rice, hence can be used to detect adulteration.
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    ThesisItemOpen Access
    Cytological studies of mutagen treated seeds of karanj (Pongamia pinnata L.)
    (CCSHAU, 2009) Ahlawat, Kavita; Saharan, R.P.
    The studies involve the treatment of Pongmia pinnata L. Pierre (Karanj) with two mutagens i.e. gamma rays and Ethyl methane sulphonate (EMS) at different concentrations. Three hundred seeds of Karanj were treated for each dose of gamma rays at the dose rate of 10 kR, 20 kR, 30 kR, 40 kR, 50 kR, 60 kR and 70 kR. Similarly three hundred seeds of Karanj were soaked in freshly prepared solution of EMS for each concentration of 0.1%, 0.2%, 0.3%, 0.4%, 0.5% and 0.6% for 6 hours. The treated seeds were sown in the nursery of the Department of Forestry, CCS HAU, Hisar in three replications. The results indicated the effect of both mutagens on the parameters studied. The percent germination decreased as the dose increased in case of both the mutagens. The treatments were significantly differ from each other in case of percent seed germination. LD50 value was found to be 20 kR in case of gamma rays and 0.3% in case of EMS treatment. Root length and plant height decreased with the increase in concentration in case of both the mutagens. The treatments were significantly differ from each other for root length in case of EMS treatment. Collar diameter showed different pattern for both the mutagens. Treatments differ significantly for collar diameter in case of gamma rays and collar diameter decreased as the dose increase, but in case of EMS, the collar diameter increased as concentration increase but at 0.4% show a slight decrease. There was no significant difference among treatments for number of leaves per plant in case of both the mutagens. Mitotic and metaphase indices show an overall decrease with increase in concentration in both the mutagens. The chromosomal abnormalities were increased with an increase in concentrations in case of both the mutagens. Anaphase bridges and distorted metaphase were the main abnormalities found in case of gamma rays and anaphase laggard, anaphase bridge and distorted metaphase were the main abnormalities found in case of EMS treatment. The use of mutagens have been suggested with precautionary measures.
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    ThesisItemOpen Access
    Combining ability analysis for spike traits and other yield attributes in bread wheat (Triticum aestivum L. em Thell)
    (CCSHAU, 2009) Gollen, Babita; Yadav, R.K.
    Line x tester analysis involving twelve diverse wheat genotypes (HD2009M, R-6, R-49, HT90, HJP81, SG215, DI717, HS-11, HS-17, HG-2, Rm-Ts13 and HS-27 as lines in combination with six genotypes (WH711, PBW502, Rm-Ts10, Rm-Ts17, C591 and RVG) as testers was conducted by raising the experimental material at the research farm of the Department of Genetics during Rabi 2008. It has been exhibited that PCV is higher than the respective GCV and however, it is slightly lower for most of the characters thus indicating a high magnitude of heritability estimate in broad sense for most of the characters in general. Estimates of combining ability and magnitude of association between various character combinations have been worked out. The results indicated the existence of adequate genetic variation for all the characters studied. Both additive and non-additive type of genetic variance prevailed. C591 and Rm-Ts10 among the testers and HD2009M, HS-17, HG-2, DI717, R-6 and SG215 among the lines were found as good general combiners for one or the other characters. HS-17 for days to heading, HG-2 for plant height and peduncle length, R-6 for 100-grain weight, DI717 for number of grains per spike, SG215 for yield per plant have high GCA effects. Higher SCA effect was observed in the cross HD2009M x PBW502 followed by HS-27 x Rm-Ts10 and HG-2 x WH711 for the character number of grains per spike indicating the preponderance of non-additive gene action in these crosses. WH711 had positive SCA effects in six, PBW502 in nine, Rm-Ts10 in twelve,Rm-Ts17 in nine , RVG in ten and C591in twelve cross combinations. Most of the cross combination involve either both lines and testers or one of the parents as showing good combining ability thus indicating the importance of both additive and non-additive type of gene action. The coefficient for genotypic correlation for most of the character combination was higher in magnitude as compared to corresponding phenotypic correlation coefficient indicating the strong inherent nature of the traits. Grain yield per plant had a strong positive association with days to heading, plant height, peduncle length, tillers per plant, spike biomass and weight of grains per spike by considering both homozygous and heterozygous nature of material. Only few cases of correlation coefficients for the character combinations as per the pattern of heterozygous material has been visualized from the homozygous material which reveals that most traits are under the influence of polygenes and the heterozygous combination for them as has been obtained in various forms depending upon the parents. The informations generated from the present investigation may be utilized by involving good general combiners and the specific crosses that are likely to transgrants for various characters individually or in combination and appropriate breeding approach has been suggested.