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20144
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Subject: Plant Breeding and Genetics × End date: 2014 × Start date: 2014 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Irradiation induced mutagenesis in sugarcane
    (2014) Mandeep Kaur; Thind, K.S.
    A study on irradiation induced mutagenesis in sugarcane was undertaken to investigate genetic variability for economic traits and red rot disease. Twelve hundred single bud setts of cv. Co J 64 were irradiated with gamma rays at 0, 10, 20, 25 and 30 Grays (Gy). The experimental material of M1V1 generation was planted during spring 2012 and second generation (M1V2) during 2013. Data was recorded on ten economic and quality traits in addition to reaction to red rot disease. Mutagenic treatments generated significant variation for germination, number of tillers/clump, number of millable canes/clump, cane height, HR brix, leaf length and single cane weight in both M1V1 and M1V2 generations indicating the potential of mutagenic treatments for creating genetic variability for different traits in sugarcane. Average cane height among different treatments ranged from 166.60 to 185.80 cm with a mean of 171.2 cm. Mean leaf length for different treatments varied from 106.30 to 114.80 cm with an average of 111.40 cm; maximum of 114.80 cm being recorded through 10 Gy treatment followed by control. Cane weight an important trait in sugar cane breeding programme ranged from 720.00 to 961.66 g. Maximum single cane weight was recorded for control followed by 10 Gy and 20 Gy treatments. The higher doses had a retarding effect on this trait. Artificial evaluation of irradiated subclones against two red rot pathotypes Cf 08 and Cf 09 using plug method revealed moderate resistance for all the mutagenic treatments. It is inferred that genetic variability could be induced in sugarcane using gamma rays for traits like germination, cane height, leaf length, HR brix, single cane weight and to red rot tolerance. The lower doses of gamma ray (10 and 20 Gy) were more effective to induce variation while higher doses have detrimental effects. The sub clones need to be further evaluated in M1V3 for their consistency in trait manifestation and future use in breeding programme.
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    ThesisItemRestricted
    Genetic diversity in relation to heterosis in maize (Zea mays L.)
    (Punjab Agricultural University, 2014) sanjeet singh
    The present investigation was conducted to estimate the magnitude of general and specific combining ability of inbred lines and crosses, respectively; mid-parent heterosis for yield component characters of maize and the association of the heterotic valve with the dissimilarity coefficient values derived from the diversity analysis using SSR markers. Forty eight crosses were made in a line x tester model by using twelve lines and four testers and all crosses with their parents were evaluated. The data was recorded on thirteen characters. The lines 1123, 1135 and 1137 were good general combiners for most of the characters studied. The estimates of gca effects revealed that inbreds 11102, 11166, 1123, 11103, 11100, LM 11 and LM 14 were good general combiners for grain yield/plant. The hybrids 1135 X LM 5, 1137 X LM 5, 1140 X LM 5, 1123 X LM 11, 1123 X LM 14, 1140 X LM 11 and 11102 X LM 11were found to be good specific combiners for most of the characters. The best crosses for per se performance and mid- parent heterosis were 1123 X LM 14, 1137 X LM 5, 11109 X LM 11, 1123 X LM 11, 1135 X LM 11 and 1135 X LM 5, 11109 X SE 546, 11109 X LM 11, 11166 X SE 546, 1137 X LM 5, respectively. Unweighted pair group method with arithmetical averages (UPGMA) available in diversity analysis computer software DARwin 5.0 was used to group the inbred lines in different clusters. Dendrogram constructed grouped the inbred lines in three clusters (C-l, C-2 and C-3). A set of thirty seven SSR primers dispersed throughout the maize genome were used to assess the genetic diversity at the molecular level. A total of one hundred and thirteen alleles were detected and polymorphism information content (PIC) value ranged from 0.218 to 0.778 with an average value of 0.565. SSR primers with di-repeats revealed a maximum mean PIC value of 0.62, followed by tetrarepeats (0.57) and tri-repeats (0.50). In order to predict the hybrid performance, utilizing SSR markers, genetic distances were calculated among the inbred lines. Correlation coefficients calculated between the genetic distances of inbred lines and mid parent heterosis and specific combining ability for various yield and yield component characters of maize were non-significant. Thus it seems rather difficult to make a generalized conclusion regarding the prediction of hybrid performance especially for grain yield, based on genetic distance measures. Keywords: Maize, combining ability, heterosis, genetic diversity.
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    ThesisItemOpen Access
    Genetic analysis of yield, component traits and rust resistance in recombinant inbred lines of lentil
    (Punjab Agricultural University, Ludhiana, 2014) Alok Kumar; Gill, Ranjit Kaur
    The present investigation was aimed to study the inheritance pattern of rust resistance, variability and association among 135 recombinant inbred lines, two parents and two checks of lentil. The parents L9-12 (susceptible) and FLIP-2004-7L (resistant) were crossed together to generate experimental material viz., F1 and segregating generations (F2 to F8). The material was developed from F3 to F8 generation following single seed descent method to develop RIL population. A set of 135 F7 and F8 RILs, both the parents and two standard checks were planted in the experimental area of Pulses Section, PAU, Ludhiana and Regional Research Station Gurdaspur during rabi 2012-13 and 2013-14. The genotypes were grown in Alpha Lattice Design with three replications. All the F1 plants gave susceptible reaction thus reflecting dominance of susceptibility to resistance. The segregation pattern of F2 generation fitted well in genetic ratio 3 susceptible: 1 resistant indicating that reaction to rust resistance was governed by single gene. In F8 generation, the segregation pattern gave a good fit to the ratio of 1 resistant: 1 susceptible further confirming that resistance to rust was under control of single gene. The analysis of variance revealed that mean squares for treatments were highly significant for all the characters. RILs having high yield potential and rust resistance were identified. Phenotypic and genotypic coefficients of variation were high for pods per plant followed by biological yield per plot. High heritability estimates were observed for most of the characters. Genetic advance was highest for biological yield per plot followed by seed yield per plot. Estimation of phenotypic correlation coefficients indicated that seed yield per plot expressed highly significant and positive correlation with biological yield per plot, harvest index, seeds per pod. Path coefficient analysis revealed that the traits biological yield per plot, harvest index, days to 50 percent flowering, days to maturity, plant height, pods per plant and primary branches had positive direct effect on seed yield per plot.
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    ThesisItemRestricted
    Development of bacterial blight resistant basmati rice doubled haploids through anther culture
    (Punjab Agricultural University, Ludhiana, 2014) Prabhjot Singh; Gill, Ranvir Singh
    The F2 population from the cross of bacterial blight (BB) resistant variety PB 3 (Xa21 + xa13) and the salinity tolerant variety CSR 30 was selected for the rapid generation of elite homozygous material in a shorter time by biotechnological inputs via marker assisted selection (MAS) and doubled haploidy. A total of 783 F2 plants were evaluated for BB resistance against most virulent and most prevalent pathotype PbXo VII under field conditions followed by molecular characterization of 303 resistant plants with gene specific markers xa13 promoter and pTA248 for xa13 and Xa21 genes respectively. From these twenty five, sixty nine and ninety seven plants were found to carry both xa13 + Xa21, xa13 and Xa21 genes in homozygous conditions respectively. The resistant plants were further used for the generation of doubled haploid plants through anther culture. Along with the resistant plants which were chosen selectively, six other F2 populations which involved PB 3, CSR 30 or RYT 3268 (BB resistant version of Basmati 370) as one of the parents were used for anther culture. Preliminary, anther culture studies were done on a set of three japonica, two indica and three basmati rice using standard anther culture protocol. Satisfactory callus induction frequency (CIF) of 38%, 5% and 4.6 % for japonica, indica and basmati genotypes respectively was observed with the standard protocol, however very poor plant regeneration could only be obtained. Based on these results refined strategy comprising of standard N6 media for callus induction and different plant regeneration media (PRM) combinations were used to generate doubled haploids (DH) from selected seven F2 populations. The CIF was found to vary from 1.4 to 11.2%. Maximum CIF was observed in the cross Pusa 1121 x RYT 3268 and minimum in CSR 30 x PB 3. Period of culturing also effected the CIF, the maximum being in anthers cultured within 4-7 days interval and minimum in 11-13 days of pretreatment. Observations on induced callus color indicated that majority of the calli were yellowish in color with a score of 4 and around 1/3rd were yellowish white with a score of 5. Among different PRM tested, the media MS V was found better having plant regeneration frequency (PRF) of 8.4% while the standard PRM had a low regeneration frequency of 3.1%. But majority of the regenerated shoots were albinos or light green and healthy plant regeneration could not be established. Thorough investigations on role of genotypes, environment and cultural conditions effecting anther culture response are required for the fine tuning of anther culture protocol for its practical applicability