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Subject: Plant Breeding and Genetics × Author: Shukla, Niharika × Start date: 1990 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Genetic studies at morphological and molecular level in maize
    (JNKVV, 2014) Shukla, Niharika; Mishra, D.K.
    Abstract The present investigation entitled “Genetic studies at Morphological and Molecular level in Maize” was carried out at Seed Breeding Farm, Department of Plant Breeding & Genetics, J.N.K.V.V. Jabalpur during Kharif 2012 and Rabi seasons of 2012-13 and 2013-14 respectively. The experimental material for the present investigation was comprised of eighty eight elite and diverse germplasm of Maize including 62 desi and 26 QPM lines (CIMMYT based lines). In which the desi lines were collected from tribal areas of Madhya Pradesh. These genotypes were planted in randomized completely block design with three replications. During year 1st (Kharif 2012) the evaluation of 88 germplasm was done at phenotypic and molecular level by conducting genetic diversity analysis among the collected germplasm of maize so as to select out the better and most diverse parents for conducting crossing programs as per 10 x 10 diallel mating design. During year 2nd (Rabi 2012-13)10 parents/lines was selected and were planted in paired parent’s arrangement for diallel mating (excluding reciprocal) in paired method for coinciding the flowering to facilitate hybridization, seed obtained from parents were harvested separately. During year 3 rd (Rabi 2013-14) 10 parents along with 45 single cross hybrids (SCH) developed during rabi 2012-13 and 1 check variety (HQPM 1) was evaluated in Randomized complete Block Design under three replications.Five competitive plants were selected from each replication for 20 quantitative traits viz; male flower initiation,days to female flower initiation, days to 50% tasselling,days to 50% silking, days to maturity ,plant height, ear height from ground, ear length, number of rows/ear, 1000-kernel weight, ear weight, stem girth, cob diameter, biological yield per plant, harvest index (%), number of prop roots, lodging (%),peduncle length, yield kg ha-1 and seed yield per plant and 8 qualitative trait viz. tassel colour, silk colour, kernel colour, kernel row arrangement, tassel type, leaf orientation, kernel type and husk cover. Data were subject to analysis to find out estimate the genetic variability, heritability, genetic advance, correlation coefficient, path coefficient analysis, magnitude of heterosis (over mid parent, better parent and standard check) ,nature and magnitude of genetic components, combining ability of parents and crosses, Graphical analysis (Wr/Vr) and to conduct the purity testing of developed hybrids through SSR markers. A Total of 29 polymorphic SSR (microsatellite) markers were used in the diversity study as well as to confirm the purity of the hybrids. The study revealed that the total number of alleles amplified were 90 with a mean value of 3.10 ± 0.23. Maximum number of allele i.e. 5 was amplified by marker Umc 1593a. Average number of bands per primer was found to be 2.896. The size of the amplified markers ranged from 100 bp (Bnlg 490) to 360 bp (ZAG 125). Specific bands were amplified by 4 primer sets viz: Bnlg 1520, Umc 1035 and Umc 1593a and Umc 1066 which separated specific Maize germplasm from remaining. Out of 29 primers used for study, a total of 17 primers i.e.Bnlg 1185, Bnlg 1520, Dupssr 17, Dupssr 34, Phi 001, Phi 961100, Phi 037 Umc 1035, Umc 1042, Umc 1066, Umc 1231, Umc 1288, Umc 1446, Umc 1593a, Umc 1859, Zag 125 and Zct 439 amplified multiple allele in all most all the 46 genotypes taken for the study of diversity analysis. The range of PIC scores of SSRs markers ranged between 0.1145 (Umc 1106) to 0.6206 (Umc 1593a). The 29 SSR markers detected a total of 90 alleles in 46 Maize genotypes. The number of alleles per locus ranged from 2 to 5 with an average of 3.10 alleles per locus. A very moderate level of heterozygosity (%) was detected in the germplasm taken for the study of diversity and it varied from 0.000 to 0.7069. Out of 29, 11 SSR loci detected no heterozygosity.Diversity in the germplasm ranged from 0.0 to 68.28%.Cluster analysis revealed two major groups i.e. group A and B. The 10 most diverse parents that were selected for the crossing programme during Rabi 2012-13 from the germplasm based on their genetic distance are CML 470, VL 101123, CML 429, CML 472, VL 1031 (QPM lines) and JLM 2, JLM 3, JLM 7, JLM 22, JLM 50 (desi lines). The 45 single cross hybrids developed through diallel was subjected to purity testing with SSR markers. In which out of 29, 13 markers were screened out which could clear cut differentiate both the (male and female) parents and confirm the hybridity of the developed F1s. The 13 markers were Dupssr 12, Zct 439, ZAG 125, Dupssr 17, Umc 1035, Umc 1231, Phi961100, Umc 1395, Umc 1066, Umc 1519, Bnlg 2086 Bnlg 490 and Umc 1106. In which Marker Zct 439 can distinguished the hybridity in maximum of 12 crosses and it’s polymorphism information content (PIC) was (0.4665) in genetic diversity analysis conducted earlier. However, marker ZAG 125 could distinguished the hybridity in 7 crosses it’s PIC was (0.4465), followed by marker Dupssr 17 which can distinguished the hybridity in 7 crosses and it’s PIC was (0.5312) for diversity analysis, marker Umc 1231 can distinguished the hybridity in 2 crosses and it’s PIC value for genetic diversity analysis was (0.5149). Similarly primer Umc 1395 can distinguished the hybridity in maximum of 3 crosses and it’s polymorphism information content was (0.4075) and the rest of the primers viz. Bnlg 2086, Phi 961100, Dupssr 12, Umc 1035, Umc 1106 and Umc 1519 could distinguished the hybridity in single crosses and their PIC values were found to be (0.5470), (0.3507), (0.4897), (0.3946), (0.1145) and (0.1537) respectively. Analysis of variance revealed highly significant differences among genotypes in respect of almost all the characters indicated the existence of sufficient genetic variability.Phenotypic and genotypic coefficient of variation was found to be higher for lodging percent, yield kg ha-1, number of prop roots ,cob diameter ,1000 kernel weight ,seed yield per plant, stem girth and ear weight. However moderate phenotypic and genotypic coefficient of variation was recorded for harvest index, ear length, number of rows/ear, peduncle length, ear height, plant height and biological yield per pant. The heritability estimates was observed high for all characters indicated that the variation observed was mainly due to genetic control.High heritability coupled with high genetic advance as percentage of mean was recorded for lodging (%), yield kg per ha, seed yield per plant, 1000 kernel weight ,cob diameter, number of prop roots,stem girth, ear weight, harvest index(%), ear length, number of rows/ear, ear height, plant height, peduncle length and biological yield per plant. Amongst all independent characters at genotypes level harvest index, exhibited the maximum positive direct effect on seed yield followed by days to female flower initiation. On the basis of the present investigation conducted the best genotype identified after both phenotyping and at molecular level for yield and its attributing traits were JLM 1, JLM 2, JLM 3,JLM 4, JLM 7, JLM 22, JLM 27, JLM 28, JLM 30, JLM 35,JLM 39, JLM 50 for desi maize and VL 101123, VL 1031, Bulk line 22, CML 429, CML 472, CML 470,HKI 161, HKI 163, BML- 6, BML-7 CML 286, HKI 13344 for QPM lines. Single cross hybrids viz. JLM 2 X JLM 50, CML 472 X VL 1031 and JLM 2 X JLM 3 revealed desirable heterosis for ear height, days to male flower initiation, days to female flower initiation, days to 50% tasselling and silking, days to maturity, number of rows/ear, 1000 kernel weight, ear weight, stem girth, cob diameter, seed yield per plant, harvest index (%), yield kg per ha and peduncle length. Parental inbred JLM 7 was found to be the good general combiner for plant height, ear height, seed yield per plant, biological yield per plant, harvest index and yield kg per ha, VL101123 was found the best combining ability for the traits like days to male flower initiation, days to 50 % tasselling, days to female flower initiation, days to 50% silking, seed yield per plant, harvest index and yield kg per ha and parent VL 1031 reported good general combining ability for days to maturity, ear length, 1000 kernel weight, ear weight, cob diameter, seed yield per plant, harvest index and yield kg per ha. The result obtained for genetic component analysis revealed the fact that Additive genetic variance was found to be non significant which was substantiated by the lower estimates of narrow sense heritability in F1 generation, confirming the predominant effect of non additive genes which was confirmed by the highly significant component in F1 generation. The approach of graphical analysis was applied to know the allelic content of the parent used in the diallel with respect to days to male flower initiation, day to female flower initiation, day 50% tasselling, day to 50% silking, plant height, ear height, number of rows/year, cob diameter, ear length, stem girth, day to maturity seed yield per plan, biological yield per plant, harvest index, yield kg per ha, numberof prop roots, peduncle length and lodging %. The regression line intercepts the Wr axis below the origin towards the negative side of Wrindicating the presence of over dominance (D