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ThesisItem Open Access Halogenation for improvement of seed yield and quality in chilli (Capsicum annum L.)(Department of Seed Science and Technology, College of Agriculture, Vellayani, 2020) Milu, Herbert.; KAU; Dijee, BastianThe research on ‘Halogenation for improvement of seed yield and quality in chilli (Capsicum annuum L.)’ was undertaken in the Department of Seed Science and Technology, College of Horticulture, Kerala Agricultural University (KAU), Vellanikkara, Thrissur, during the year 2018-2020. The study aimed to assess the impact of halogenation on growth and field performance of treated seeds, as well as its influence on seed quality during ambient storage. The study comprised of two experiments. In experiment I, the field performance of halogenated chilli seeds was assessed. Freshly harvested seeds of chilli variety Anugraha treated with different doses of halogens indirectly through a carrier were the treatments used. The experiment was laid out in a Randomised Block Design (RBD) with four replications and five treatments viz., T1: Control (Untreated), T2: CaOCl2 + CaCO3 (2 g each/kg seed), T3: CaOCl2 + CaCO3 (4 g each /kg seed), T4: Iodine crystal + CaCO3 (50 mg each/kg seed), T5: Iodine crystal + CaCO3 (100 mg each/kg seed). Observations on growth and yield parameters were recorded at appropriate growth stages. The results revealed that seed yield attributes such as fruits per plant, fruit weight, seed yield per plant and hundred seed weight were significantly influenced by the treatments. Among the CaOCl2 treatments, T2 (CaOCl2 + CaCO3 @2 g each/kg seed) recorded higher values for fruits per plant, fruit weight and seed yield per plant. Of the two seed invigoration treatments with iodine, T5 (Iodine crystal + CaCO3 @100 mg each/kg) performed superior for fruits per plant, fruit weight, seed yield per plant and hundred seed weight. Seeds obtained from Experiment I were used for seed storage studies (Experiment II). The seeds were dried to a moisture content less than eight per cent, bagged in 700 gauge polyethylene bag and stored under ambient conditions for six months. Samples were drawn at monthly intervals and various seed quality parameters were analysed. The experiment was laid out in Completely Randomized Block Design (CRD) with five treatments (T1 to T5 as in experiment I) and four replications. Seed quality parameters such as germination per cent, vigour indices and seedling dry weight declined with the progress of storage, whereas electrical conductivity of seed leachates increased over the storage period. Significant differences were observed among the treatments for germination per cent from first month onwards to the end of storage. All treatments including the control maintained MSCS (Minimum Seed Certification Standard) of 60 per cent germination till the end of six months of storage. At the end of storage, T2 (CaOCl2 + CaCO3 @2 g each/kg) followed by T5 (Iodine crystal + CaCO3 @100 mg each/kg) recorded higher germination per cent and vigour indices. The influence of halogen treatments on seed infection was found significant at the start and end of storage. Treatments, T5 (Iodine crystal + CaCO3 @100 mg each/kg seed) and T2 (CaOCl2 + CaCO3 @2 g each/kg) were found superior with lower infection. In order to identify treatments effective for improvement of seed yield and quality, scoring and ranking were carried out for all the characters studied under experiment I and for germination per cent and vigour indices in experiment II. While considering the total score obtained by the treatments for both the experiments, T2 (CaOCl2 + CaCO3 @2 g each/kg seed) was found to have multiple benefits of enhancement of growth and seed yield attributes and maintenance of seed quality during storage. T2 was followed by T3 (CaOCl2 + CaCO3 @4 g each/kg seed) and T5 (Iodine crystal + CaCO3 @100 mg each/kg). Hence, it is concluded that seed treatment with CaOCl2 + CaCO3 @2 g each/kg seed was effective in improving seed yield and quality in chilli variety Anugraha. The treatment is simple and chemicals are easily available hence farmer friendly. The study may be extended to other chilli varieties to standardise the dosage for recommendation.ThesisItem Open Access Standardization of hybrid rice seed production for Kerala using three line system of breeding(Department of Seed Science and Technology, College of Agriculture, Vellayani, 2020) Arunkumar, C; KAU; Jayalekshmi, GThe present study entitled “Standardization of hybrid rice seed production for Kerala using three line system of breeding” was carried out in the College of Agriculture, Vellayani and Integrated farming system research station (IFSRS), Karamana during 2019-2020, with an objective to standardize GA3 and brassinosteroid and to optimize the planting ratio in restorer line (R line) and male sterile line (A line) to get maximum hybrid seed yield under Kerala condition. The study comprised of two experiments, the phenological studies in male sterile line (Aline) and standardization of GA3 and brassinosteroid dose for the planting ratio of A, R line in 6:2 and 8:2. Phenological studies of the CMS line CRMS31A were taken under protected condition during different growth stages. The production of tillers on male sterile line started at 23.3 days after sowing. At maturity, the plant height reached up to 123.33 cm length with 18.1 total numbers of tillers. The sterile plant produced total of 91 leaves and the flag leaf had 39.01 cm2 area. The initiation of the panicle was observed on 58.9 days old plants and panicles were developed between internodes of the first stem. The panicle initiation was associated with the beginning of stem internodes formation and the initiated panicle was microscopic in size (2-4 mm) with a fuzzed tip inside the main culm. The increase in size of the panicle primordia and its upward extension inside the leaf sheath were detected inside the rapidly elongated culm. The booting stage was started at an age of 67.2 days then the first panicle was emerged on 74.1 days old plant and fifty percentages of panicles were emerged within a week. Flag leaf angle play a vital role in the percentage of seed filling (fertility percentage) by acting as a barrier between pollen from the male parent and the CMS plants spikelets. The average flag leaf angle of CRMS 31 A was 15.60 which was very less when compared to traditional varieties. The CRMS 31 A had taken 85.5 days to anthesis and taken 9 days to finish the anthesis of whole spikelets on panicle. In the second experiment, field evaluation of hybrid seed production in the cross between CRMS 31A and the identified restorer „Remya‟ was done in the fields of IFSRS Karamana for standardising the planting ratio and the doze of growth hormones. This experiment was laid out in Randomized Block Design (RBD) with three replication during March-July 2020 (Virippu). The parental lines were sown in staggered dates according to the duration of the CMS line and the pollen Restorer line. The sowing of male and female parents were planned to achieve the synchronization in flowering. The R line was sown in three staggered dates. i.e., one at three days before the sowing date of CMS lines, the second set along with CMS line and the third set were sown three days after the sowing of CMS lines. The sterile R line and pollen parent were sown in the planting raio of 6:2 and 8:2 and two doses of GA3 (50 and 70 ppm) and brassinosteroid (2 and 6ppm) were sprayed at 15-20% heading and 35-40% panicle emergence. Observations on eight morphological and five yield traits were recorded during the crop production. All the traits used in the study showed significant variations. The mean performance of CRMS 31 A observed better performance in morphological and yield parameters at 70 ppm GA3. The treatment T5 (GA3-70 ppm, BRs-2ppm with 6:2 planting ratio) recorded the highest panicle exsertion (8.707 cm), plant height (145.653 cm) and flag leaf area (64.747 cm2) followed by T6 (GA3-70 ppm, BRs- 2ppm with 8:2 planting ratio). The highest productive tiller (25.00), total tiller (27.00), number of leaves (135.00) and leaf angle (26.600º) were observed in T6 (GA3-70 ppm, BRs-2ppm with 8:2 planting ratio) and followed by T5. The higher concentration of BRs reduced the flag leaf area (42.767) in T3 (GA3-50 ppm, BRs-6ppm with 6:2 planting ratio). The morphological traits of the male sterile line was improved with respect to panicle exsertion, flag leaf area, productive tillers and leaf area index by the application of GA3 70ppm and BRs 2ppm. The 1000 grain weight was higher in T3 (19.400g) followed by T5 (17.267g) and T6 (16.500g) and the least was in control treatment T4 (13.733g) and T7 (13.900g). The highest number of filled grain per panicle (33.00 nos) and lowest number of unfilled grains per panicle (17 nos) were observed in T5 with 70ppm GA3. The highest number of unfilled grains per panicle was found in control plants (T4 and T7). The Spikelet fertility percentage was more in T5 (19.507%), followed by T3 (16.140%) and less fertility percentage was observed in control plants T4 (7.127%) and T7 (7.397%). Highest seed yield per plot was recorded in T6 (1489.320g) followed by T5 (1355.746g) lowest seed yield was observed in control plants T4 and T7. The drawback of CMS line could be minimized by the application of hormones and improve seed set can be obtained. Humidity and the wind velocity prevailing in the location was not favorable for free flow of pollen and better seed set. So a more favorable season has to be tested for better yield. In this study the doze of Brassino steroids 2ppm and GA 70 ppm in both planting ratios of 6:2 and 8:2 had given substantially higher yield over the control. So hybrid rice seed production in Kerala can be enhanced by spraying of GA3 70ppm and brassinosteroid 2ppm at 15-20% heading of tillers and 35-40% panicle emergence. The row ratio of the female parent to the restorer parent can be 8:2 considering the increased seed yield realized. More seasons and locations have to be tested to identify the best season and location for hybrid rice seed production in Kerala.ThesisItem Open Access Effect of high temperature stress on seed fillings and nutritional quality of rice (Oryza sativa L.)(Department of Seed Science and Technology, College of Agriculture, Vellayani, 2020) Kandanulu, Pravallika; KAU; Beena, RKandanulu Pravallika Date: 26-06-2020 2018-11-162 Time: 2.00- 2.30 pm EFFECT OF HIGH TEMPERATURE STRESS ON SEED FILLING AND NUTRITIONAL QUALITY OF RICE (Oryza sativa L.) The present study entitled “Effect of high temperature stress on seed filling and nutritional quality of rice (Oryza sativa L.)” was conducted in the Department of Seed Science and Technology, College of Agriculture, Vellayani during the period from 2018-2020 with the objective to study the effect of high temperature stress on seed filling and nutritional quality of rice. The extent of variation for various seed quality parameters, enzymes and yield parameters were assessed as an indicator of high temperature stress from three rice varieties namely Prathyasa, Hraswa and Manuratna. These varieties were collected from Regional Research Station (RRS), Moncombu and from Agricultural Research Station (ARS), Mannuthy respectively. The experiment was laid out in CRD with two treatments such as control and high temperature conditions and replicated thrice. The plants were kept in a temperature controlled polyhouse from seedling to maturity stage. Seed quality and enzyme parameters were analyzed at 30 and 50 days after 50 percent flowering and yield parameters were taken at harvest stage. Seed filling parameters recorded at milky and dough stage had revealed that high temperature stress condition resulted an increase of reducing sugar (14.810 mg g-1), carbohydrates (898.310 mg g-1), starch (14.961 mg g-1), and flavonoids (14.385 mg 100g-1) compared to control. However, amylose (17.692 %), seed protein (4.081 %), and anthocyanin (15.490 mg 100g-1) showed reduction under high temperature stress condition. Activity of invertase was reduced under high temperature condition compared to control in all varieties from 15 to 30 days after 50 % flowering. Under high temperature condition, spikelet fertility percentage and grain yield/plant were reduced compared to control condition. Among three varieties, highest grain yield/plant (22.790 g/plant) and spikelet fertility percentage (80.598 %) under high temperature was recorded by Prathyasa. Average reduction of grain yield/ plant and spikelet fertility percentage under high temperature was 18.733 g/plant and 74.245 % respectively. Percentage of yield reduction was maximum for Hraswa variety (27.57 %) when compared to varieties Prathyasa (21.1 %) and Manuratna (21.18%). Pollen viability percentage was reduced under high temperature condition compared to control. Prathyasa recorded the highest pollen viability (86.358 %) and Hraswa recorded the lowest pollen viability (77.948 %). Average reduction in pollen viability under high temperature condition was 82.653 %. There is significant difference for seed protein content among varieties. Highest seed protein content was recorded by Hraswa. There is no significant difference between Prathyasa and Manuratna for reducing sugar content, amylose, starch, invertase and yield. High temperature stress in rice recorded an increase of reducing sugar, carbohydrates, starch and flavonoids. Grain yield/ plant, spikelet fertility percentage, amylose, anthocyanin, seed protein and invertase activity were reduced under high temperature condition in all the varieties. Flavonoids are the secondary metabolites that are increased in high temperature condition and it helped in defense. High temperature had adverse impact on yield, spikelet fertility and pollen viability and the impact were greater in Hraswa variety. The correlation analysis revealed that under high temperature condition yield showed positive and significant correlation with total carbohydrate, starch, anthocyanin, spikelet fertility and pollen viability. Hence it is important to identify the rice varieties which possess the major seed filling parameters which play a vital role in increasing thermotolerance that result in giving a satisfactory grain yield even under conditions of heat stress.
