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Open Access
Diallel analysis in rice bean(Vigna umbellata( Thunb.) ohwi & ohashi)
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1999) Preeti, S V; KAU; Radha Devi, D S
A diallel analysis in ricebean (Vigna umbellata (Thunb.) Ohwi and Ohashi) was carried out in the Department of Plant Breeding and Genetics, during 1997 - '98. The experimental material consisted of six parental lines and 30 F I hybrids, laid out in Randomised Block Design with three replications. The six parents were 3 LG, 5 LG, 6 LG, 8 LG, 9 LG, and 100 LG obtained from the germ plasm collection maintained at NBPGR, Thrissur. The observations were recorded on yield and yield attributing characters. Significant differences were detected among the mean performance of the genotypes, for all the characters studied. The combining ability analysis carried out by Method I, Model I of Griffing's approach (1956), revealed that the parent, 8LG was the best general combiner for most of the yield attributing traits. Among the crosses, 8LG x 3 LG exhibited outstanding sea for seed yield per plant. The crosses involving 8 LG were found to be good specific combiners. The combinations involving 3 LG and 6 LG also gave good specific combining ability effects. The numerical analysis by Hayman's approach indicated overdominance for almost all characters, which was confirmed by graphical analysis. The dominance of decreasing alleles in the parents was indicated by the negative value of F for all characters except, plant height, length of pods and number of seeds per pod. An almost equal distribution of genes with positive and negative effects was indicated by the ratio of H2 to 4H} for all the characters. The regression coefficient of covarince between parents and their offsprings in each array (Wr) on variance of all progenies in each parental array (Vr) did not- differ from unity, for plant height, length of pods, seed yield, 100 seed weight, days to maturity and protein content, indicating that assumption of non-allelic interaction was satisfactory for these characters. The Vr - Wr graph indicated that the parents were genetically divergent for days to first flowering, number of pods per plant, number of seeds per pod, 100 seed weight, days to maturity, root weight and nodule weight. Manifestation of heterosis was seen for all the characters studied. Among the hybrids, 8 LG x 3 LG was the most outstanding for yield and yield related characters. The crosses, 8 LG x 9 LG, 8 LG x 100 LG, 6 LG x 9 LG, 100 LG x 8 LG and 6 LG x 3 LG also performed better in yield and yield attributing characters. In general, hybrids involving 8 LG and 6 LG were found to be heterotic.
Open Access
Induction of polyploidy in kacholam
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1996) Ajithmohan, N K; KAU; Pushkaran, K
A trial on induction of polyploidy in Kaempferia galanga L. was undertaken at the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, during the period 1994-'95. A local selection Vellanikkara collected from the genetic stock maintained at AICRP on M & AP was used for the study. The objective was to create variability in kacholam by developing polyploids. The rhizomes of the crop were treated with colchicine for inducing polyploidy. Five concentration of colchicine viz., 0.05, 0.15, 0.25, 0.35 and 0.45 per cent (C2 to C6, C1 being control i.e., 0%) was tried for two time durations viz., four hours and six hours (T1 and T2), the same treatment being repeated on two consecutive days. Two methods of treatment were tried the first (M1) being chemical application in a hole drilled close to the sprouting bud and the second (M2) being the ordinary cotton swab method. Rhizomes with two different stages of bud sprouting were used: (1) with just emerging buds (S1) and (2) buds at an advanced stage of sprouting (S2). The treated rhizomes were planted in the field and their growth was examined. In the end of the crop season, 18 variant plants were identified and they were put to detailed morphological and cytological study in the next growing season. Mitotic study of the parent material confirmed that the chromosome number of kacholam is 55. Of the 18 variants identified one was found to contain 110 chromosomes in the somatic cells. As kacholam is proposed to be a pentaploid the induced polyploid must be a decaploid. The polyploid was obtained from the treatment combination S1M1T1C6. It was characterised by small plant size and reduced vigour. The leaves were thick with reduced size. Stomatal size increased conspicuously with their numbers reduced. The rhizome development was found retarded and the per plant yield was also less. The rhizome morphology was on par with the normal plants. The plant flowered neither in the first season nor in the second. In addition to the polyploid, there other stable variants were obtained from the experiment. They were also characterised by reduced vigour and yield.
Open Access
Reproductive biology and enzyme studies in ocimum
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1997) Fancy, Parameswaran; KAU; Presannakumari, K T
The present study on "Reproductive biology and enzyme studies in Ocimum spp." was undertaken at the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara during the period 1994-1996 with a view to make a comparative evaluation of the reproductive biology and phosphorylase enzyme activity of different species of Ocimum. The four species of Ocimum viz. O. tenuiflorum, o. gratissimum, o. canum and o. basilicum collected and maintained in the Department were used for the study. The different species of Ocimum varied significantly in the time taken for inflorescence development, completion of anthesis in an inflorescence, number of flowers per inflorescence and distance between verticils. Species level variations were also observed in seed moisture content, seed density, l000-seed weight and seed dormancy period. Flowers of the four selected species were identical in basic structure although there existed variation in size, colour, hairyness and shape of floral parts. Anthesis occurred earlier in o. canum than the other three species. Pollen grains of Ocimum were hexacolpate and reticulate. However, species level difference existed in the size, shape and fertility of pollen grains. No self incompatibility mechanism existed in the four species studied. The floral morphology and protandrous nature makes the species adapted to cross pollination. Insects and ants are the main agents of pollination. Comparison of Sanctum and Basilicum groups revealed that Sanctum group which includes o. tenuiflorum and O. gratissimum required longer time for inflorescence development than Basilicum group which includes o. canum and O. basilicum. Verticils were closer in the inflorescence of Sanctum group than Basilicum group. Sanctum group produced less conspicous flowers with sessile bracts and yellow pollen grains. In this group anther dehiscence occurred in bud stage. Basilicum group produced conspicous flowers with pedicellate bracts and white pollen grains. Anther dehiscence was after flower opening in this group. Dormancy break was sudden in Sanctum group and gradual in Basilicum group. Moisture content of Ocimum seeds was positively related to phosphorylase enzyme activity. Phenol content was negatively related to both moisture content and phosphorylase enzyme activity of the seeds.
Open Access
Cytological and Biochemical Changes in Aged and Osmoprimed Seeds of Chilli
(Department of Planting Breeding and Genetics, College of Horticulture,Vellanikkara, 1999) Thara Manohar; KAU; Nandini, A
Studies Oil seed quality aspects in storage or chilli variety Jwalasakhi and Ujwala were undertaken in the Department of Plant Breeding and Genetics, College of Ilort icult urc, Vel lanikkara during 1997 to 1998 to study the di fferent types of cytological and biochemical changes in aged seeds or chilli, to investigate the effects of osmopriming in chilli seeds and to study the feasihility of osmopriming in overcoming physiological and genetic deterioration of stored seeds. The germination studies conducted during the ten months of storage period revealed that chilli seeds lost viability completely from the nineth month of storage onwards in amhient conditions. Hydroprimed seeds germinated to the tune of 13 and 20 per cent in Jwalasakhi and Ujwala respectively. Under this conditions osmopriming with chemicals PI':(; and Na Cl significantly improved this germination per cent to 40 as observed during the tenth month of storage. The chemical Na Cl with concentration 1.5 MPa and 48 hours duration was found the hest. Among the varieties Ujwala responded bcuer compared to Jwalusukhi. Irrespective of the chemical all osmopriming treatments produced uniform seedlings compared to control and the germination was completed within seven days under ideal conditions. In general vigour index and root shoot ratio also expressed similar results to that of germination. Studies 011 biochemical characteristics revealed a progressive loss of activity of mitochondrial dehydrogenase and soluble protein with ageing. The electrical conducuvity of seed leachate also increased with period of storage revealing the loss of mcmbrune integrity resulting ill leakage of cell contents outside the cell membrane. . Osmopriming treatments were ahle to repair this membrane damage to a good extend and increase the level of dehydrogenase activity and soluhle protein content compared to _ control. In hoth varieties sodium chloride with - 1.5 MPa was found the hest treatment. Among varieties Ujwala responded hetter than lwalasakhi. Cytological studies revealed u reduction in mitotic index values during storage irrespective of the variety. Osmopriming was found to improve the mitotic index values over hydropriming and untreated control. Any type or chromosomal aberration was not detected during the ten months of ageing period. l lere also sodium chloride with I. S M 1 'a was found to be superior. It can be concluded that I. The loss of viability in chilli seeds is mainly due to biochemical lesions '") Osmopriming was found beneficial after two months of storage in chilli seeds, because chilli seeds could retain the innate capacity to germinate and produce quality seedl ings up to two months of storage period. 3. PHI-ooon and Na Cl C<.I1l be used as an osmoticum for post storage priming treatments in aged chilli seeds. Na Cl can be advocated more economically compared to PLG.
Open Access
Induced mutations in interspecific hybrids of abolmochus
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1996) Animon, G; KAU; Gopimony, R
The F1 seeds of the cross between Abelmoschus esculentus cv Kiran and the semi- wild species, Abelmoschus manihot were exposed to four different doses (10, 20, 30 and 40 KR) of gama rays and their effects in the first generation were studied. The percentage of seed germination decreased with increasing doses of gamma rays. The treated hybrids have shown delyed germination compared to the control. The survival of plants was found to decrease with increase in dose of the mutagen. The rate of growth of plants and plant height were found to decrease by the treatment with gamma rays. Various chlorophyll and morphological varients were observed in the irradiated population. An increase in pollen fertility was noticed in the irradiated hybrids. But the increased pollen fertility did not show any effect on the seed set. Irradiation delayed the formation of flowers and fruiting. The mean values for number and weight of fruits did not differ significantly among irradiated treatments and was on par with the control F1. The treated hybrids were found to be on par with the control F1 for yellow vein mosaic disease incidence and the important diseases affecting bhindi. The hybrids irradiated at higher doses had become more susceptiable to fruit borer incidence. The hybrids represented more towards the semi-wild parent and have shown considerable heterosis over the cultivated parent and semi-wild parent for most of the economic characters. The hybrids were vigorous in growth habit compared to the parents. The hybrid treatments exhibited significant positive heterosis for days taken to first flowering and last fruiting over the cultivated parent. The hybrids treatments exhibited significant positive heterosis for number of flowers, number of fruits and weight of fruits over both the parents. Significant negative heterosis over the cultivated parent was shown for fruit length by the hybrid treatments. Significant negative heterosis over the cultivated parent for fruit borer incidence was shown by the control and the hybrids irradiated at 10 and 20 KR. All the hybrid treatments manifested significant negative heterosis over the cultivated parent for YVMD incidence. The mutagenic effectiveness in inducing chlorophyll mutations was found to increase with increase in dose of the gamma rays. The mutagenic efficiency estmated on the basis of lethality and injury increased with increase in dose of gamma rays. On sterility basis, the 30 KR treatments was the most efficient.
Open Access
Heterosis and combining ability in melon
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2000) Deepthy, R; KAU; Wilson, D
The current research programme on 'Heterosis and combining ability in melon (Cucumis melo (L.) var. conomon) was carried at the Department of Plant Breeding and Genetics, College of Agriculture, VeIl ay ani during 1998- 2000. The objectives were estimation of various genetic parameters, heterosis and combining ability effects of parents and hybrids. The experimental material consisted of seven parents and their 21 F 1 hybrids (without reciprocals). Analysis of variance revealed highly significant difference among the genotypes for all the 21 characters studied. The genotype P3 topped in mean performance for yield and many yield attributes. The hybrids P2 x P6 and P2 x P3 were superior in yield and fruit characters, whereas P6 x P7 was the best for keeping quality, yield and crop duration. Genetic parameters like PCV, GCV, heritability and genetic advance were high for keeping quality, yield, sex ratio and mean fruit weight. Environmental component of variation was negligible for majority of traits. Significant heterosis was observed for all the characters studied. P3 x P 4 showed maximum standard heterosis for yield whereas, P2 x P 6 showed maximum relative heterosis and fruit characters and earliness traits. Variance due to GCA and SCA were significant for all the traits studied. P3 was the best general combiner for yield, fruit diameter, mean fruit weight and fruit length and P2 was the best for node characters and crop duration. The hybrid P6 x P7 was the best specific combiner for yield. Combining the mean performance, SCA effects and standard heterosis, P2 x P6 was identified as the superior cross in terms of yield and yield attributes whereas P 4 x Ps was the best for various flowering traits.
Open Access
Characterisation and evaluation of the rice cultivar njavara
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2000) Srinivasa Reddy, G; KAU; Elsy, C R
Characterization and evaluation of the rice (Oryza saliva L.) cultivar Njavara was undertaken in the Department of Plant Breeding and Genetics and Biochemistry Laboratory, College of Horticulture, Vellanikkara during 1997-1999 with an aim to characterize Njavara genotypes based on morphological and biochemical studies and to evaluate its nutritional qualities. Morphological characterization indicated that the thirteen Njavara genotypes were distinct among themselves and the Njavara genotypes NI (Njavara type from Mulloorkara, Thrissur), N2 (Njavara type from Chittoor, Palakkad), N5 (Njavara type from Edavanna, Malappuram), NIl (Njavara type from Pattambi, Palakkad) and NI3 (Njavara type from Thootha, Palakkad) yielded on par with the check variety Ptb-IO, eventhough they were having extra short growth duration compared to Ptb-I 0. Biochemical characterization revealed the possibility of utilizing peroxidase, esterase and protein polymorphism for identifying the Njavara genotypes especially NI (Njavara type from Mulloorkara, Thrissur) , N2 (Njavara type from Chittoor, Palakkad), N3 (Njavara type from Chittoor, Palakkad) and N4 (Njavara type from Chittoor, Palakkad) and also for the identification of Njavara as a cultivar. Selecting some other isozymes coupled with enzyme activity studies and opting for molecular markers were the other strategies suggested for characterization of Njavara genotypes. Majority of the Njavara genotypes expressed high protein content than Ptb-l O. The genotypes N2 (Njavara type from Chittoor, Palakkad) and N8 (Njavara type from Alwaye) were recommended to be included in weaning and invalid foods due to high protein content. The genotypes N2 (Njavara type from Chittoor, Palakkad), N3 (Njavara type from Chittoor, Palakkad) and NI2 (Njavara type from Thrissur) appeared to have higher number and content of free amino acids. Most of the Njavara genotypes had intermediate amylose and as such may not have any problem with respect to consumer preference. Starch grain characterization revealed that starch grain size could be used for varietal characterization in conjunction with morphological and biochemical markers. Absence of flavonoids in Nj avara grain indicated its nonaromatic nature. The genotype N7 (Njavara type from Tellicherry, Kannur) was found to have better digestibility due to low amylose content, high amylase activity and high soluble carbohydrate content. Variability studies indicated that fat content, straw yield and grain yield provided a good genetic base for selection. Correlation and path studies revealed that grain yield could be improved by simultaneous selection for high straw yield and longer leaves while selection for wider leaves, longer ligules, increased number of days to 50 per cent heading, longer panicles and long duration genotypes favour high free amino acid content. Low amylase activity, short and narrow leaves, shorter panicles, low 1000 grain weight, slender grains, short duration genotypes and smaller starch grains were observed to favour high protein content and selection for tall culms, high 1000 grain weight and bold grains was found to favour high amylase activity:
Open Access
Genetic and physiological analysis of ratooning in rice
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2000) Ambili Nair, S; KAU; Rosamma, C A
The present investigation 'Genetic and physiological analysis of ratooning in rice (Oryza sativa L.)' was conducted at the Agricultural Research Station, Mannuthy during 1999-2000 to study the main crop as well as ratoon crop behaviour of different rice genotypes. The study was carried out to determine genetic variability among the different genotypes used. The study was also aimed at identifying morphological and physiological characters for a genotype of rice with high productivity when main and ratoon crop yields are combined together, through correlation and character association studies. Suitable selection indices were also formulated for identifying superior genotypes. Among the 50 genotypes evaluated in the main crop 24 showed regrowing ability. Of these five varieties viz. CO 43, IR 20, White Ponni, Ponmani and Mangala Mahsuri recorded better ratoon performance. The ratoon crop characters were less pronounced compared to the main crop characters except chlorophyll contents. But the above mentioned genotypes 'exhibited a higher intensity of character expression in both crops compared to the remaining genotypes. The estimates of GCV, heritability and genetic gain were high in the caseofratoon crop for most of the characters studied. Present study revealed that higher total yield can be achieved with a main crop having long duration and increased number of unproductive tillers plant". Ratoon yield can be improved by a better performing main crop with characters such as long duration, more number of grains panicle", more number of unproductive tillers plant" and reduced grain production day". Ratooning ability was considered as an index of the ratoon performance but in the present study ratooning ability recorded a negative direct effect on yield, indicating that this cannot be used as a true index to assess the ratoon performance. The various genetic and physiological analysis thus revealed that the varieties viz. IR 20, Mangala Mahsuri, White Ponni and Ponmani can be recommended as genotypes suitable for ratooning in Kerala. By using these about one third of the main crop yield can be achieved without increasing the land area. Total yield recorded 1;>y these genotypes were also significantly high.
Open Access
Genetic analysis of certain clones, hybrids and inbreds in cocoa
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1998) Rose Mary Francies, KAU; Achamma Oommen
Genetic studies in cocoa (Theobroma cacao L.) using various population viz., clones, biclonal crosses, biclonal pair crosses and inbreds were undertaken in College of Horticulture, Kerala Agricultural University, Thrissur, during 1994-97. The study assessed variability, association of yield attributes and relative importance of these attributes for yield variation using multiple regression and path analysis. Selection indices, inbreeding depression and limits to genetic diversity for heterosis were also worked out. Wide spectrum of variability existed in the populations studied. The highest variability was observed in yield of dry beans/tree and precocity of bearing (pods/tree - 5 years from planting), whereas, traits pod width and bean width showed low variability. Clones GI 10.2, S 27.16, GI 14.17 of Clonal base population, hybrids H'8 (GI 5.9 x GII 23.3), H2 (M 13.12 x GI 5.9) of Series IV biclonal crosses and hybrids H4 (M 16.9 x GII 19:5), H3 (M 16.9 x GII 20.4) of Series 11 biclonal crosses, exhibited superior yield - performance. Yield however, recorded only moderate heritability and therefore moderate expected genetic advance. Strong correlation was observed for yield with pod weight, dry weight/bean and efficiency index but not with precocity of bearing, chlorophyll contents and net photosynthesis rate. Multiple regression and path analysis revealed the importance of dry weight/bean, bean size and efficiency index in determining the yield in cocoa. High correlation exhibited by many traits was due to indirect effects. Selection index for yield, based on the above traits viz., dry weight/bean, bean length, bean thickness and efficiency index recorded a relative efficiency of 150.35 per cent over direct selection. Inbreeding depression was observed for growth traits. The rate of depression was more in the second inbred generation as compared to that in the first inbred generation. Number of hybrids exhibiting relative heterosis in desirable direction ranged from one (eg. pod width, bean length and thickness) to seventeen (number of beans/pod). Considerable genetic divergence among clonal genotypes was evident. Results indicated that the chances for occurrence of a high frequency of heterotic crosses and high values of heterosis are more, when the parental divergence is moderate.

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