http://localhost:8080/handle/123456789/5225 2026-04-18T21:08:52Z 2026-04-18T21:08:52Z S. M. AHSAN-WZ-ZAMAN http://localhost:8080/handle/123456789/5187 2024-03-30T06:45:32Z 2020-01-01T00:00:00Z

GENETIC ANALYSIS OF YIELD AND ITS COMPONENTS IN F 1 AND F 2 POPULATIONS OF TOMATILLO (Physalis ixocarpa Brot. / Physalis philadelphica Lam.) S. M. AHSAN-WZ-ZAMAN A tomatillo (Physalis ixocarpa Brot. /Physalis philadelphica Lam.) core collection consisting of five parental genotypes viz., SAU tomatillo 1 (G1), SAU tomatillo 2 (G2), PI003 (G3), PI004 (G4) and PI005 (G5) was explored for variation in plant growth, yield and fruit quality traits, in order to develop improved plants with desirable traits from subsequent tomatillo diallel crossing program. Twenty F populations of tomatillo were derived from 5x5 diallel crosses to combine desirable genes from different parents and to produce pure-breeding progeny superior in many respects to the parental types. F 1 population was developed in order to select superior genotyes as the greatest genetic variability exists in the F xviii 2 population and the most effective selection occurs there. The experiments were conducted at replicated plots following RCBD design in the central experimental field and central laboratory of Sher-eBangla Agricultural University, Dhaka during Oct/2017 to Mar/2020. Analysis of variance for agromorphogenic traits of five parental and twenty hybrids of tomatillo showed significant variation in yields and in quality traits. Maximum yield was found in parent G3 (740.67 g/plant), in F 1 population G1×G3 (1060.66 g/plant) and in F population G1×G3 (1021.33 g/plant). Cross ability analysis of tomatillo showed excellent cross ability in G3, G1 and G4 and their crosses in three years. Estimation of heterosis, assessment of combining ability and gene actions for different characters were performed. Maximum standard heterosis was found 2 in G1×G3 (19.35%) followed by G1×G2 (10.94) for yield/ha. These crosses deserve attention for their heterotic responses. The ANOVA of combining ability analysis showed highly significant results for most characters which suggested the presence of both additive and nonadditive gene action for inheritance. The GCA effects revealed that the parents G1and G3 showed the best general combiner. The highest positive significant SCA effect was found in G3×G1 (11.51**) and the cross G1×G3 was the best specific combiner for yield per ha. Genetic analysis in F 1 , F populations revealed that both additive and non-additive genetic effects were important for different characters. Extent and direction of heterosis in F 2 varied greatly for different characters. Diallel analysis was performed using the Hayman’s approach chiefly comprises the aspects, Hayman’s ANOVA, Vr, Wr analysis with graphical representation and components of variation and genetic parameters. Vr-Wr graph suggested that partial dominance and/or over dominance gene actions were involved for all the characters in F . The ranks of parental dominance were: G5 > G4 > G1 > G2 > G3 in the increasing order for the trait yield. Magnitude of E for each character was much less compared to their respecting D and H1 suggesting the characters were influenced less by environment. The ratio of (H2/4H1) estimated the average frequency of positive and negative 1 alleles in all the parents. The significant correlation was found in fruit pH, lycopene content (502) and fruit moisture content at genotypic level and in fruit moisture and lycopene content at phenotypic level. Based on the value of yield components, the highest selection score was found in G1×G3 (1065.57) having ranked 1 followed by G1×G2 (1032.15) with rank 2. The lowest ranked genotype was found in G2×G4 (701.66) with rank of 20 followed by G4×G2 (725.09) having ranked 19. The highest selection score was found in G1×G3 (18.719) having ranked 1 followed by G3×G1 (17.409) with rank 2 for quality traits. G1×G3 and G1×G2 could be recommended for further selection trial for higher yield towards variety development of tomatillo. Different gene actions underlying these traits provides valuable insight in the further selections and can be used to support breeding strategies for tomatillo crop improvement. A Thesis submitted to the Faculty of Agriculture Sher-e-Bangla Agricultural University, Dhaka in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY IN GENETICS AND PLANT BREEDING

2020-01-01T00:00:00Z TALUKDER, MOHAMMAD ZUBAIR ISLAM http://localhost:8080/handle/123456789/5186 2024-03-30T06:40:44Z 2020-01-01T00:00:00Z

GENETIC ANALYSIS OF COTTON (Gossypium hirsutum L.) GENOTYPES FOR DROUGHT TOLERANCE TALUKDER, MOHAMMAD ZUBAIR ISLAM Drought is a major constraint that adversly affect the cotton yield and its fibre quality. In order to ascertain drought tolerant genotypes of cotton, three experiments based on morphological, physiological, fibre quality, yield and yield components of cotton genotypes under drought condition were conducted at two different locations. The morphological and physiological study was performed at Sher-e-Bangla Agricultural University, Dhaka. The fibre quality and yield experiment was conducted in the farmers‟ field at Godagari, Rajshahi. The fibre quality tests were executed at Fibre testing laboratory, Dhaka and Cotton Research Farm, Sreepur, Gazipur of Cotton Development Board. The duration of the experiments was from April, 2017 to March, 2020. Fifty cotton genotypes and four different treatments for drought stress were outlined in CRD for morphological and physiologica experiment and RCBD for fibre quality and yield experiment with three replications. Significant genotypic variations were observed for all the characters studied in all three experiments. Among all genotypes CB-12 is the highest ranked genotype for number of reproductive branches at early flowering stage and BC413 is the highest ranked genotype for root length. Heritability values in broad sense were relatively high for almost all the characters except number of vegetative branches. There is significant positive correlation between the number of reproductive branches and shoot length, shoot root length ratio, root diameter and total biomass of root both at genotypic and phenotypic level. Path analysis also revealed positive direct effect of these four traits on number of reproductive branches indicating these traits would help in further selection progress. According to DRI values, among fifty genotypes, twenty could be included in tolerant group at early flowering stage of cotton. Diversity studies revealed, fifty cotton genotypes were grouped into 8 clusters. The genotypes with high shoot length and no. of reproductive branch was observed in cluster IV. High root diameter and no. of lateral root in drought stress remain together in a cluster VII. Based on relative selection index (RSI) and drought response index (DRI) Ra-16 and BC-442 could be selected as tolerant genotype to drought at early flowering stage. In physiological studies at early flowering stage, among all genotypes CB-14 is the highest ranked genotype for pollen viability followed by water retension capacity and water uptake capacity. SR-16 is the highest ranked genotype for proline content. BC-394 was also higher ranked genotype for proline content as well as for water saturation deficit and relative water content. High heritability coupled with high genetic advanced in percent of mean was recorded for water saturation deficit, water retention capasity, water uptake capacity, membrane stability index and proline content indicating additive gene action controlling these traits and selection based on these traits will be rewarding. Correlation coefficient revealed positive and significant correlation among pollen viability and total chlorophyll as well as nitrogen content. Path analysis also showed positive direct effect of chlorophyll and nitrogen content on pollen viability. Based on RSI and DRI, BC-512, Ra-3, BC-413, CB-14, BC-385 and BC-394 could be selected as drought tolerant genotypes based on physiological study at early flowering stage. Among twenty five selected genotypes from previous two experiments, BC-433 had the highest rank for seed cotton yield per hectare followed by JA-13/R, BC272, BC-510. The lowest days to first boll bursting rank was found in CB-8 followed by Ra-16 and CB-10. The highest rank for Ginning Out Turn (GOT) was found in BC-272 followed by CB-11 and BC-442. High heritability coupled with high genetic advance at percent of mean was found for the traits, no. of vegetative and fruiting brunches, no. of bolls per plant, seed cotton yield per hectare indicating additing gene action controlling these traits and selection would be effective. Significant positive correlation with yield was found for the characters plant height, days to first square initiation, days to first boll split, no. of fruiting branch, no. of bolls per plant, single boll weight and seed index. Path analysis revealed positive direct effect of plant height, no. of bolls per plant and single boll weight on yield. Based on RSI and DRI values BC-415 is best ranking genoype for yield followed by BC-433 and BC-442, CB-14, CB-8 and BC-394. Regarding quality traits, genotypes JA-13/R had the longest fibre length, reflectance degree and fibre strength followed by BC-385, BC-433, CB-14, Ra-4, Ra-16 and BC-442. RA-08/9 had the highest micronnaire followed by BC-385 and CB-13. Ra-16 had the highest fibre strength followed by JA-13/R, Ra-3. Uniformity index had significant positive correlation with fibre length both at genotypic and phenotypic level. Path analysis also showed positive direct effect of uniformity index on fibre length. Based on SRI and DRI value, BC-510 is the highest ranking genotype followed by Ra-4, BC-385, BC-433, BC-413 and BC-462. Five genotypes as BC-415, BC-433, BC-442 and CB-14 for highest yield and three genotypes as BC-510, Ra-4, BC-385, BC-433, BC-413 and BC-462 for best quality fibre could be recommended to the farmers‟ of northern region of Bangladesh. Based on days to first square initiation, days to first flower initiation, days to first boll split and days to first boll bursting, BC-462 required further trial for earliness under drought prone areas. A Thesis Submitted to the Faculty of Agriculture Sher-e-Bangla Agricultural University, Dhaka in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY IN GENETICS AND PLANT BREEDING

2020-01-01T00:00:00Z SHELLY, NASRAT JAHAN http://localhost:8080/handle/123456789/5185 2024-03-30T06:33:45Z 2020-01-01T00:00:00Z

GENETIC ANALYSIS ON YIELD, OIL CONTENT AND QUALITY CHARACTERISTICS OF SELECTED Brassica rapa L. GENOTYPES SHELLY, NASRAT JAHAN The investigation was carried out at the experimental field and in the Biochemistry and Agricultural Chemistry and Environmental Science laboratory of Sher-e-Bangla Agricultural University, Dhaka during Nov/2017 to Dec/2021 with seven selected Brassica rapa genotypes to develop elite breeding lines with high yield potential, short duration and high oil content with better quality. BARI Sar-6 had the highest yield (8.41 g plant -1 ) but had very long duration (110 days), while Tori-7 had the lowest yield (4.25 g plant -1 ) with short duration (81.66 days), on the other hand Brown Special matured early (80.66 days) with moderate yield (5.88 g plant -1 ). Most of the F s were intermediate type between their parents for morphological characteristics and performed better than their both parents for most of the quantitative traits. Tori-7 × Brown Special matured early in 80 days, while the highest yield (27.67 g plant -1 ) 1 had recorded in Tori-7 × Yellow special. The highly significant and the highest negative heterosis for maturity had recorded in BARI Sar-6 × Brown Special over the better parent (-23.33%) and in BARI Sar-6 × BARI Sar-17 over the mid parent (-13.22%). For yield plant , Yellow Special × Tori-7 showed the highly significant and the highest positive heterosis over both the parents (352.37% and 245.01% respectively). Considering the highest positive (except earliness) and the highly significant GCA effects, Brown Special was the best general combiner for earliness and yield plant -1 , while based on SCA effects, the cross BARI Sar-6 × Brown Special was the best for earliness and BARI Sar-15 × Brown Special was the best for yield plant -1 . Therefore, these genotypes might be used for further improvement of these traits. Generation mean analysis revealed that, F 1 s were superior over their both parents but F s means indicated inbreeding depression in most cases. BC 2 performed better than BC 1 2 in most of the crosses for yield plant -1 . The significant scaling tests for most of the traits across the crosses indicated the presence of epistasis but insignificant χ2 values in most cases indicated the absence of epistasis and thus, six-parameter model (Hayman, 1958) had suggested to explain the nature of gene actions. Significant negative additive gene effects for most of the traits across the crosses indicated non-additive gene action and selection might be ineffective but in those cases significant positive additive gene effects had found selection might be effective. While heterosis breeding could be explored for significant positive dominance gene effects in most other cases. However, where, both additive and dominance gene effects were significant and positive, reciprocal recurrent selection might be suggested. For oil content, the parent - Yellow Special, F 1 - Brown Special × Yellow Special, F 2 - BARI Sar-14 × Yellow Special and in both BC and BC - Tori-7 × BARI Sar-14 contained the highest amount of oil, 45.05%, 39.04%, 37.71%, 38.98% and 38.57 % respectively. Among the parents - Tori-7, in all F 2 1 , F 2 and BC - Tori-7 × Yellow Special and among BC - Yellow Special × BARI Sar-6 contained the highest amount of poly unsaturated fatty acid, 16.98%, 19.27%, 21.54%, 21.57% and 16.47 % respectively. Among the parent - Tori-7, in all F 1 , F 2 2 and BC 1 -Tori-7 × Yellow Special and among BC - Yellow Special × BARI Sar-6, contained the lowest amount of erucic acid, 44.97%, 45.37%, 45.42%, 45.49% and 46.67 % respectively. So, these genotypes might be used for further development of these traits. A Thesis submitted to the Faculty of Agriculture, Sher-e-Bangla Agricultural University, Dhaka, in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY IN GENETICS AND PLANT BREEDING

2020-01-01T00:00:00Z