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Open Access
Studies on induced mutations in rice (Oryza sativa L.)
(Division of genetics and plant breeding ,Agricultural college and research institute , Coimbatore., 1971) Gopinathan Nair, V; KAU
Open Access
Androgenesis in rice (Oryza sativa L.) breeding
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2004) Chandrahasan, V T; KAU; Dijee Bastian
An investigation was carried out in rice, at the College of Horticulture, Vellanikkara to produce doubled haploid lines through anther culture technique. The study included production of a hybrid between IR 36 (ovule parent) and PTB 45 (pollen parent), evaluation of parents and hybrid, culturing the anthers of F1 to produce doubled haploids and analyse the effect of growth regulators (2,4-D, Kn, IAA and IBA) and carbon source (sucrose and maltose) on callus induction. There was significant difference among the parents and hybrid. The hybrid recorded significantly different values for plant height, panicle length, grains / panicle, grain weight and grain yield / plant. Among the 24 treatments used for anther culture, callus induction was observed in 11 treatments. Callus induction percentage ranged from 0 to 4.18. Maximum callus induction percentage was recorded in N6 medium supplemented with maltose 60 mg/l, 2, 4-D 2mg/l and Kn 0.5 mg/l (4.18%) followed by N6 medium supplemented with maltose 60 mg/l, 2, 4-D 2 mg/l and Kn 1mg/l (3.32%). A significant increase in anther culture efficiency was observed when sucrose was replaced by maltose in the presence of growth regulators 2,4-D/Kn but not in the presence of IAA/Kn. Callus induction frequency was high in 2,4-D/Kn combination followed by IAA/Kn combination irrespective of carbon source. IBA/Kn combination was totally non-responsive. Main effects of 2, 4-D and Kn were significant, but there was no interaction between 2, 4-D and Kn when sucrose was used as carbon source. Among the two levels of 2, 4-D, 3 mg/l (0.6%) was superior to 2 mg/l (0.24%) and among the two levels of kinetin 0.5 mg/l (0.71%) was superior to 1 mg/l (0.12%). Main effects of 2, 4-D only was significant when maltose was used as carbon source. Main effect of 2, 4-D indicated that there was significant reduction in callus induction response when level of 2, 4-D increased from 2mg/l (3.75%) to 3mg/l (2.31%). Sixty six calli were obtained through anther culture of which 57 were embryogenic calli and the rest non-embryogenic calli. The percentage of embryogenic calli (86.45%) was higher than non-embryogenic calli (13.6%). 2, 4-D/Kn combination produced more number of embryogenic calli (88.3%) than IAA/Kn combination (66.7%). Thirty green plants and five albinos were obtained from regeneration medium. The frequency of green plant and the albinos were 85.71 per cent and 14.29 per cent respectively. Regeneration frequency of embryogenic and non-embyogenic calli were 27.19 per cent and 22.22 per cent respectively. Among 30 green plants obtained , 21 were homozygous diploids and the rest haploids. Frequency of spontaneous doubling was 70 per cent. Of the 30 regenerated plants taken for hardening 24 survived and all were observed for grains per panicle and seed setting percentage. The values of grains per panicle and seed setting percentage ranged from 87 to 106 and 89.79 to 95.33 respectively.
Open Access
Standardisation of selection criteria for cocoa hybrids
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1998) Raji Varghese; KAU; Pushkaran, K
Investigation on standardisation of selection criteria for cocoa hybrids was conducted at Cadbury-KAU Co-operative cocoa Research Project (CC RP) Farm of Kerala Agricultural University, Vellanikkara during 1994-96. Twenty nine hybrids grown under Progeny Trial I and their 18 parents maintained in CYT-I were used for the study. The influence of seedling height and girth on yield was more pronounced in the case of seedlings one year after sowing than with those of 4 mas, 5 mas and 6 mas. The vegetative vigour measured by the height and diameter of trunk was found to be better correlated with precocity. The correlation coefficients of pod characters viz., length, width and weight of pods, number of beans, wet bean weight and pericarp thickness and seed characters viz., length, width, thickness and dryweight worked out between hybrids and female parents showed significant relationship in the case of pod length (r = 0.649) and number of beans (r = 0.606). But with mid parental value, the hybrids showed high correlation for the characters pod length, pod weight, number of beans, seed length, seed width and seed thickness (0.65, 0.45, 0.86, 0.70, 0.76 and 0.70 respectively). Heritability estimated by regressing offspring on female parent was high for the characters pod width, seed length and seed width (0,7, 0.64 and 0.78 respectively). Among the 29 hybrids studied, the hybrid H-4 of the cross GI 10.3 x GVI 54 was found to be promising in terms of both pod and wet bean yield. With the seedling characters of hybrids taken one year after sowing, a multiple regression equation for wet bean yield was fitted as: Y = 43 + 0.195 x1 + 3.70 X2 Where, x1 and X2 are height and girth of one year old seedlings respectively. This can be taken as a seedling selection criteria for cocoa hybrids.
Open Access
Genetic analysis of segregating generations of irradiated interspecific hybrids in okra (Abelmoschus spp.)
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1997) Sophia John; KAU; Manju, P
A study* was. conducted in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during l996-'97 to estimate the extent of variability generated in the f 2M? and F3M3 generations as a result of hybridisation and hybrid irradiation of the interspecific hybrids between A. s esculenins and A. manihot and also to isolate high yielding yellow vein mosaic disease resistant lines from among the segregating generations In the l-^M-, generation, the irradiated treatments were found to be late flowering and had more number of leaves per plant, flowers per plant and fruits per plant Irradiation was found to increase pollen sterility and was maximum in 10 kR However seed set was lower for the irradiated treatments. Average fruit weight and weight of fruits per plant was maximum in plants belonging to the treatment 20 kR. Fruit length and girth were found to increase with increasing radiation doses. Number of ridges per fruit, fruiting phase and plant duration were higher in the irradiated treatments when compared to 0 kR and was maximum in 40 kR Plant height was highest in the treatment 30 kR Irradiation was found to increase YVM disease incidence and fruit and shoot borer incidence and it was maximum in 30 kR among the irradiated treatments. However a few high yielding YVM disease resistant plants resembling the cultivated parent were also observed in 30 kR ■Genotypic coefficient of variation, heritability and genetic advance were high for number of branches per plant and number of seeds per fruit in all the irradiated treatments in F2M2. High heritability with high genetic advance were observed for leaf number, number of flowers per plant, Iruits • ' per plant and pollen sterility in 20 kR and 30 kR. Significant positive * . correlation of number of leaves per plant, flowers per plant and fruits per plant with weight of fruits per plant and also among themselves was observed in all the irradiated treatments in F2M0. Average fruit weight and fruit yield A* • 0 per plant were positively correlated in treatments 0 kR, 10 kR, 40 kR, P, and P2. % In F3M3 the irradiated treatments were found to be late flowering and had more number of leaves, branches, flowers and fruits per plant. Pollen sterility was lower for the irradiated treatments, when compared to the unirradiated treatment and was lowest in 30 kR. However the number of seeds per fruit was more in 30 kR compared to the other treatments excluding parental treatments. Irradiation was found to decrease average fruit weight but fruit yield per plant was more for the irradiated treatments due to the larger number of fruits and was maximum in 40 kR. Length of fruit increased with increasing radiation doses. Significant differences among the irradiated treatments were not observed with respect to number of ridges per fruit. Irradiation was found to increase the fruiting phase as well as plant duration. Plant height was maximum in 10 kR when compared to all the other treatments. Yellow vein mosaic disease incidence was high in the cultivated parent and the higher dose radiation treatments viz , 30 kR and 40 kR. From the present study *a few recombinants which resembled the cultivated parent, with high yield and YVM disease resistance could be isolated from 30 kR, which suggested that 30 kR could be ideal radiation dose for evolving high yielding YVM disease resistant lines in okra. Fruit and shoot borer incidence was highest in the cultivated parent and was also high in 30 kR. High to moderately high genotypic coefficient of variation was observed.lor number of branches per plant, leaves per plant, flowers per plant, fruits per plant, weight of fruits per plant and number of seeds per fruit in all irradiated treatments in F3M3. High heritability and genetic advance were observed lor number of fruits per plant, weight of fruits per plant, flowers per plant and pollen sterility in all the irradiated treatments. Number of leaves per plant, flowers per plant and fruits per plant were positively correlated with fruit yield per plant in all the treatments while average fruit weight had significant positive correlation with fruit yield per plant in 0 kR, P, and P2 in the F3M3 generation. As a future line of work, high yielding, YVM disease resistant plants assembling the cultivated parent which have been isolated from the treatment 30 kR will be further evaluated for a few more generations and if found superior and YVM disease resistant it will finally be developed into a YVM disease resistant variety.
Open Access
Genetic analysis of high yielding rice varieties of diverse origin
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1998) Vanaja, T; KAU; Luckins, C Babu
The research project 'Genetic Analysis of High Yielding Rice Varieties of Diverse Origin' was carried out in the College of. Horticulture, Kerala Agricultural University, Vellanikkara, Thrissur during the period 1995-'98. The major objectives of the study were to understand the genetic architecture of high yielding rice varieties of diverse origin so as to evolve appropriate breeding methodology, to isolate promising lines having the new ideotype concepts from the segregating generations and to identify alternative source of cytoplasmic male sterile system suitable to warm humid climatic conditions experienced in Kerala. The study, about components of heritable variation revealed that the characters, number of panicles m-2 number of tertiary branches panicle-1, yield ha-1, spikelet sterility percentage and alkali spreading value exhibited high broad sense heritability coupled with high expected genetic advance and high genotypic coefficient of variation. High broad sense heritability and high expected genetic advance coupled with moderate genotypic coefficient of variation were manifested by the characters, namely, height of plant at harvest, second uppermost internodal length, length of flag leaf, ratio of vegetative phase to reproductive phase, number of spikelets panicle-1 number of grains panicle-1, LIB ratio of grain, milling percentage, amylose content, volume expansion ratio and water uptake. '1 Correlation studies revealed that the principal yield determining components in rice are harvest index, number of tertiary branches panicle-1 number of panicles m-2 number of grains panicle-1 number of spikelets panicle-1. ratio of vegetative phase to reproductive phase, 1000 grain weight, number of days to 50 per cent flowering, number of days to harvest and spikelet sterility percentage. While selecting genotypes for higher yield potential, emphasis should be given for comparatively long vegetative period, short period from panicle initiation to 50 per cent flowering and long ripening period. A selection model was formulated consisting of the characters, namely, yield ha-1 harvest index, number of days to harvest, number of tertiary branches panicle-1 ratio of vegetative phase to reproductive phase and number of grains panicle-1 Cluster analysis revealed that there was no parallelism between geographical distribution and genetic diversity. The 56 genotypes representing different eco-geographical regions were grouped into nine clusters based on genetic distances. Combining ability studies showed that both additive and non-additive gene effects were important, with predominance of non-additive gene action, for all the characters except for 1000 grain weight, second uppermost internodal length and height of plant at harvest. The varieties Vytilla3, Mahsuri, Mattatriveni and Karthika were identified as good general combiners. The varieties Mahsuri, Karthika, Vytilla 3, Mattatriveni and IR62030-18-2-2 showed pronounced cytoplasmic effect on yield and various yield contributing characters. The crosses Vytilla 3 x Mattatriveni, Mahsuri x Vytilla-3 an,d Mahsuri x Mattatriveni are recommended for recombination breeding. The crosses Vytilla 3 x IR36, Vytilla 3 x IR60133-184-3-2, PK3355-5-1-4 x Bhadra, Vytilla 3 x Mattatriveni, Karthika x Bhadra, PK3355-5-1-4 x Karthika and PK3355-5-1-4 x IR620'30-18-2-2 are recommended for heterosis breeding. The cytoplasm of Vytilla 3 (an improved saline tolerant variety of Kerala) was identified as an alternative source for cytoplasmic male sterility in rice, suitable to warm humid tropical climate, experienced in Kerala. The varieties IR36 (international check) and Hraswa (extra short duration high yielding variety of Kerala) are the proposed maintainer lines. Mattatriveni is the proposed restorer line for the proposed IR36 'A’ line and Hraswa 'A’ line. The generation mean analysis using six parameter model revealed that both additive and non-additive gene effects played an important role in the inheritance of yield and important yield components, with predominance of dominance, additive x additive and dominance x dominance type of gene effects. Results of inbreeding depression indicated absence of reduction in vigour in the F2 generations for yield and all other yield attributes. Investigation on pattern of inheritance of kernel colour revealed that kernel colour in rice is a complex qualitative character. Each red and white colour may be separately controlled by two or more sets of genes having both inhibitory and duplicate type of gene interactions with predominance of inhibitory type gene interaction. From 22F2 generations, seven early stabilized promising lines and 26 promising segregants were selected. Two early stabilized lines were found to possess most of the ideotype features proposed by IRRI with preferable cooking quality characters. Their further evaluation and multiplication are being carried out at the Agricultural Research Station, Mannuthy, Kerala Agricultural University. By hybridization, it was possible to successfully transfer the non sticky nature and red kernel colour of Mattatriveni to a high yielding Taiwan variety whose kernel is white and sticky on cooking. The gene action studies revealed that there is ample scope for yield improvement in rice both through pedigree breeding and heterosis breeding. As yield and yield components were found to be under the control of all the three types of gene actions namely, additive, dominance and epistasis, intercrossing of early segregating generations derived from multiple crosses seems to be the best suited method of breeding for yield improvement in rice. Future line of studies suggested 1. Conversion of the already obtained cytoplasmic male sterile F1 crosses to fully sterile CMS lines by repeated back crossing with the respective recurrent parents. 2. Screening from the segregating populations of these cytoplasmic male sterile crosses for 100 per cent cytoplasmic male sterile lines. 3. Confirmation of the restoring ability of the proposed Mattatriveni 'R' line and identification of other restorers. 4. Incorporation of the sterile cytoplasm of Vytilla 3 into other elite genotypes other than IR36 and Hraswa. 5. Screening for cytoplasmic male sterile system in other saline tolerant lines. 6. Screening of promising segregants selected, for high yield and quality with multiple resistance to pest and diseases, for developing varieties suited to various climatic and soil conditions of Kerala.
Open Access
Combining ability in bhindi (Abelmoschus esculentus (L) Moench)
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1995) Rajani, B; KAU; Manju, P
The study was carried out in the Department of Plant Breeding and Genetics, College of Agriculture , Vellayani during 1994-95 to estimate the combining ability of six genetically divergent parental strains of bhindi and their 30 F1 hybrids obtained by crossing the six parents in a diallel pattern. The magnitude of heterosis and nature of gene action governing the yield of fruits and other important yield attributes was also elicited through Hayman's numerical and graphical approach. The combinig ability analysis by the Method 1 of Griffing's (1956) approach revealed that the parent P4 (NBPGR/TCR 864) was the best general combiner for yield and a few yield related characters. Among the hybrids P1 X P4 (NBPGR/TCR 893 x NBPGR/TCR 864) exhibited outstanding s.c.a effects for yield. Non addictive gene action was found to govern days to first flowering number of flowers per plant, length of fruit, girth of fruit, weight of single fruit, weight of fruits per plant and number of seeds per fruit while the remaining characters were governed by addictive gene action.
Open Access
Studies on seed dormancy in rice (Oryza sativa. L.) with special reference to short duration varieties
(Faculty of Plant Breeding and Genetics, Agriculture College & Research Institute, Coimbatore, 1961) Gopinathan Nair, V; KAU; Ponnaiya, B W X
Work done in cereals and other crop plants on the factors related to seed dormancy (causes, tissues involved, stage of maturity at harvest, variation in period and genetics), which are important from a practical breeding point of view, has been critically reviewed with special reference to rice. Studies were undertaken on six short duration varieties of rice and their hybrids to estimate the period of dormancy, to understand the relative roles of the hull and the embryo and also to understand the mode of inheritance of the character. A new method was adopted in the estimation of dormancy. The period required for germination from flowering, determined by germination tests at periodic intervals, rendered a reliable estimate of inter and intravarietal variability for germination and formed the criterion for comparison of varieties and hybrids.
Open Access
Genetic analysis of seed dormancy and productivity in groundnut (Arachis hypogaea L.)
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1997) Tessy Joseph; KAU; Namboodiri, K M N
Investigations on genetic analysis of seed dormancy and productivity in groundnut (Arachis hypogaea L.) were carried out in the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara from 1992-95. The objective of the study was to find out the gene effects of biometric traits and seed dormancy in groundnut, so as to suggest appropriate breeding methodology and parental combinations to evolve domant, high yielding and early manuring varieties. The findings of the study are briefed below. Evaluation of 28 genotypes (14 domant and 14 non domant) for two seasons revealed that wide range of variability existed among them. Donors for specific traits were identified . The genotypes were also genetically diverse and could be grouped into four clusters. The line x tester analysis with three lines and five testers revealed that additive gene effects governed most of the characters except pod yield and number of mature pods , for which , non addictive gene effects were important. To harness both the types of gene effects pedigree method followed by selection in advanced generations will be fruitful.
Open Access
Inheritance of resistance to leaf hopper [Amrasca biguttula biguttula (Ishida)] in okra, Abelmoschus esculentus (L.) Moench.
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2003) Deepthi, Sivanandan; KAU; Sunny, K Ommen
Okra is an important vegetable crop grown in India and abroad for its fresh green pods. The leafhopper Amrasca biguttula biguttula is a major sucking pest of okra causing high damage to plants. High frequency of fruit picking and repeated application of chemical pesticides to tackle the hopper menace, often leaves toxic residues in the fruits. So it is inevitable that pest resistant varieties should be developed. Hence a study was undertaken to study the genetic variability, for yield and its component characters as well leafhopper resistance indices in a collection of okra genotypes, to estimate the combining ability and heterosis as well as gene effects involved in the inheritance of these characters using line x tester analysis. Forty okra germplasms collected from vanous sources were evaluated simultaneously for yield and leaf hopper resistance. ANOV A revealed that the treatments varied significantly for leafhopper resistance and also there was significant variation among treatments for yield and yield attributes viz., days to first flowering, leaf axil bearing first flower, number of primary branches, number of fruits per plant, length of fruit, girth of fruit, weight of fruit, yield per plant duration. Six genotypes exhibited resistance to the leafhopper throughout the crop duration. High values for phenotypic and genotypic coefficients of variation was recorded for number of primary branches followed by leafhopper population count. High heritability was exhibited by yield per plant followed by duration. Maximum genetic advance was observed for number of primary branches followed by yield per plant. Correlation analysis indicated that most character combinations had higher genotypic correlation coefficient than phenotypic correlation coefficient. Yield exhibited significant and positive correlation with number of fruits and average fruit weight and negative significant association with leaf axil bearing first flower, leafhopper population count and leafhopper injury score. Path analysis was carried out for nine biometric as well as two leafhopper injury indices which had high correlation with yield. Highest positive direct effect was exhibited by number of fruits while the highest negative direct effect on yield was recorded for leafhopper population count per plant. Resistant as well as susceptible genotypes were selected based on leafhopper population counts and leafhopper injury score. Five resistant lines (female parent) viz., Nemom (T21), re 45792, Venjaramood (T23), AE 279 and Palappur (T20) and three susceptible testers (male parent) viz., Venganoor (T1S), Aruna (T37) and Kalliyur (T24) were selected as parents for L x T analysis. These were crossed in a line x tester fashion to produce 15 hybrids. During L x T programme highly significant sea as well as gea effects were obtained for yield. Lt was the best line while T 2 was the best tester. Among hybrids L3 x T 2 was the best considering leafhopper resistance as well as yield and yield attributes. Negative and significant sea effects were observed for days to first flowering and leafhopper population count. It possessed all the desirable characters like high yield, greater weight and girth of fruits and number of fruits. It is also an early flowering type. The ratio of additive to dominance variance was less than one for most of the traits studied including leafhopper population counts and leafhopper injury , scores, indicates the predominance of non-additive gene action. Since there is preponderance of non additive gene effects for characters such as yield and its components as well as leafhopper resistance parameters, exploitation of hybrid vigour is an appropriate breeding approach where yield and leafhopper resistance are considered.

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