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ThesisItem Open Access CHARACTERISATION OF PRE-HARVEST SPROUTING TOLERANT LINES OF WHEAT(2023) Dutta, Sumon; Borah, PrakashOne of the first and most significant cereal crops to be produced worldwide is wheat (Triticumaestivum L). It is the primary cereal crop and the principal source of nourishment for millions of Indians, second only to rice. Wheat is traded more globally than all other crops combined. With a global production of 749 million tonnes in 2016, wheat surpassed maize as the second-most produced crop. The crop is grown on 30 million hectares of land overall in India, producing 93 million tonnes at a productivity of 2.98 tonnes per hectare. In Assam, wheat is sown in November and harvested in March or April, which frequently falls within the pre-monsoon rainy season and negatively affects seed production. Pre-harvest sprouting can significantly reduce the nutritional value and processing quality of seeds in addition to decreasing wheat production. Breeding for pre-harvest sprouting tolerancein wheat is under progress at the University and a few lines have been developed. Characterisation of these lines following DUS test guidelines for various morphological characters and confirmation of pre-harvest sprouting tolerance is required for recommendation of the lines for cultivation in pre-harvest sprouting prone areas with aberrant rainfall pattern. In the present study, evaluation of five pre-harvest sprouting tolerant lines (PHST 1-1, PHST-1-5, PHST-4-3, PHST-7-3, PHST-7-3-1) along with two check varieties (DBW-39 and HD-2967) for DUS characteristics as per Guidelines for the Conduct of Test for DUS (PlantVarietyJournalofIndia.Vol.1(1),2007) was carried out in a field experiment laid out in Randomised Block Design with three replications. The study also involved evaluation of the lines pre-harvest sprouting and incidence of diseases in field conditions. Significant variation was observed among the genotypes for characters such as plant growth habit, ear: time of emergence, flag leaf: waxiness of sheath, ear: waxiness, plant length, ear: length, awn: length, grain:colouration with phenol, 1000-seed weight and yield. The check varieties DBW-39 and HD-2967 and a pre-harvest sprouting tolerant line PHST 1-1 has shown in-ear sprouting. Among these three genotypes, the highest in-ear sprouting was observed in HD-2967. No major wheat diseases were observed during the study. However, all the genotypes were affected by Sooty mold/ Black head mold as the crop was kept in the field for prolong period to expose the crop to pre-monsoon shower for the purpose of observation of in-ear sprouting.ThesisItem Open Access EFFECT OF PRIMING ON QUALITY OF TRUE POTATO SEED(2023) Das, Prasurjya; Sarmah, BhaswatiPotato is the world’s most important tuber vegetable, with a vital yet often under- appreciated role in the global food system. True potato seeds are small, round, and dark in color, and they are produced by the sexual reproduction of potatoes. A major constraint in potato production is the lack of good quality of seeds. Quality seed is one of the most important elements in successful potato cultivation. Unlike traditional potato propagation methods that use tubers, True potato seed (TPS) offers several advantages such as disease-free starting material, easier transportation, and increased genetic diversity. However, they have low acceptability due to low uniformity in heterogenous seedling populations and low vigour. Seed priming is a pre-sowing treatment that aims to improve seed performance and accelerate germination. TPS priming is a technique used to enhance the germination and early growth of true potato seeds. In the present study, the parameters Germination percentage(G%), seed vigour index(SVI), Germination index(GI), seedling dry weight(SDW), vigour at 30DAT(V@30DAT), plant height(PH), Number of tuber plant(NTPP), Tuber yield per plant(TYPP), Tuber dry matter(TDM) and Incidence of major diease(IOD) high significant variation at P=0.05 was observed among 10 treatments. Among the treatments the highest germination percentage, seed vigour index and germination index is shown in the seeds primed with gibberellic acid followed by melatonin and T. harzianum. Seeds primed with Melatonin recorded maximum vigour at 30DAT. Among the treatments highest number of tuber per plant, tuber yield per plant and tuber dry matter is shown by the seeds primed with poly ethylene glycol (PEG). Therefore the experimental findings revealed that priming with Gibberellic acid and polyethylene glycol enhances the seedling and tuber characters producing superior result relatively compared to other results and can be promoted for further large scale trials.ThesisItem Open Access SEED FORTIFICATION WITH ZINC AND ITS’S EFFECT ON SEED QUALITY AND NUTRITIONAL QUALITY OF RICE(2023) Kumari, Nisha; Deka, Sharmila DuttaRice (Oryza sativa L.) a member of family Poaceae is a cereal foodstuff which forms an important part of the diet of many people worldwide. It is a staple food for more than 60% of the worldwide population, making it the second-most consumed cereal grain. Rice cultivation in our country is done mostly in the humid tropical and sub- tropical climate which is characterized by high temperature and relative humidity; hence storage may lead to rapid deterioration of seeds. Usually crops seeds are stored from harvest till next growing season and storage duration may vary from months to a year or more. However, the vigour and viability of seeds rapidly decline during storage, and the use of low vigour seeds frequently results in poor field performance, weak seedling growth, and, ultimately, low yield. Assam Agriculture condition with high rainfall and high humidity is not ideal for medium and long-term seed storage. Sometimes it is challenging for seed growers to save the seeds with Indian Minimum Seed Standard for even one growing season. Invigoration of aged seeds after storage is important to enhance the seed quality. For the present investigation, seeds of rice variety Gitesh were taken having two lot, lot 1 (one year old seed) and lot-2 (freshly harvested seed). These two lots were primed for 12 hours with water, ZnSO4(100,200,400,800 mg/liter) and ZnO (100,200,400,800 mg/liter) followed by shade drying for 12 hours and it was evaluated to see the effect of seed treatment with zinc on seed quality and nutritional quality of rice. Seed primed treated with treatment T4 (100 mg/liter ZnSO4) was found to be the best treatment for increasing the germination and field parameters viz., germination first count, germination final count, germination index, root length shoot length seedling dry weight, SVI-I, fresh and dry weight of plant, panicle length, number of grains/panicle and yield/Plant. However, treatment T7 recorded highest (800 mg/litre, ZnSO4) field emergence % and chlorophyll content. Zinc is the most important and limiting micronutrient for rice growth and yield. Reports suggested that seed yield and nutritional attributes can be manipulated with seed treatment with zinc. In the present investigation treatment T9(200 mg/litre, ZnO) recorded highest zinc and total soluble protein content. Significant improvement in germination % was observed with zinc treatment in both the new and old seed lot. However, lot-1(i.e., old seed) where germination % was below IMSC, but increased to certification standard with Zn treatment. Seed yield/plant was found to have positively and highly significantly correlated with all the germination attributes.ThesisItem Open Access EFFICACY OF BIOAGENTS IN STORABILITY OF MAIZE SEEDS (Zea mays L.)(2023) Kurmi, Kishore Kumar; Sarma, AkashiMaize (Zea mays L.) is one of the most important cereal crops in the world, ranking third next to rice and wheat. Its production plays a significant role in ensuring food security and is used both for direct consumption as well as for second cycle produce in piggery and poultry farming. The estimated losses is as high as 59.48% in maize grains after storing them for 90 days in the traditional storage structures. Inadequate post-harvest pest management practices leads to huge amount of losses during storage and also limits it’s storage life to a great extent. The present investigation helped to find out whether the bio control strategies are effective against stored grain pest and can improve the storage quality of seed w.r.t their physiological parameters. The pooled analysis of variance revealed highly significant variation for all quality parameters of maize seeds for treatments and period of storage up to 270 days while significant results were obtained for infestation w.r.t. time of storage up to 270 days. ANOVA for the biochemical characters after 270 days of storage showed significant results for the treatments studied. Highest mean performances were recorded in seeds treated with black pepper powder in plastic air tight container for germination percentage, viability, seed vigour index and alpha amylase activity, whereas highest lipid peroxidation value was recorded in seeds treated with pongamia oil in HDPE bag. Seed infestation was comparatively lower in seeds treated with neem oil in both the packaging material and lowest moisture content was recorded in seeds treated with black pepper powder. Therefore, the experimental findings revealed that storing seeds with black pepper powder in plastic air tight container produce superior results for quality traits of maize seeds and storing seeds with neem oil in plastic air tight container gives better protection to stored seeds against infestation and can be prescribed for large scale trials.ThesisItem Open Access EFFECT OF SOLAR BUBBLE DRYER ON SEED QUALITY OF PADDY(2023) Serto, Eunice Suoneiyang; Sharma, K. KPaddy (Oryza sativa L.), is the staple food of over 3 billion people and is the most widely cultivated food crop. Although rice holds great importance as a crop, significant amount of rice ends up going to waste as a result of challenges in post-harvest management. Post-harvest loss reduction has the potential to increase the national food security. Drying and storage are two key post-harvest processes to improve yield in rice production. Storing of freshly harvested seeds without properly drying to safe level of moisture may affect the quality of seeds. Assam is identified for its poor storability and lack of proper storage facility makes it difficult for its storage up to the next season resulting in deterioration of seed quality parameters. In the present investigation, freshly harvested seeds of three varieties (Ranjit sub-1, Numali and Mahsuri) were taken from the ICR farm of Assam Agricultural University, Jorhat. Dryer performance of Solar bubble dryer (SBD) was evaluated and compared with the sun drying method. Higher air and grain temperature were recorded in SBD as compared to the sun drying method. Grain temperature inside SBD did not exceed the critical limit 43°C which ensured quality and prevented damage of the paddy seeds. In the same duration of time, SBD showed advantage over sun drying in achieving faster reduction of moisture content (%) for all the three varieties. After drying, seeds were stored in different packaging materials viz., T1 (seeds dried in SBD + stored in HDPE bag), T2 (seeds dried in SBD + stored in poly-lined jute bag), T3 (seeds dried in SBD + stored in IRRI super bag) and T4-control (seeds sun dried + stored in PP bag). Seed quality parameters were recorded at 30 days interval for 6 months (180 DAS). Analysis of variance showed significant variation among treatments and storage periods for all the seed quality parameters. Irrespective of the varieties, T1 (seeds dried in SBD + stored in IRRI super bag) gave the best result with respect to all seed quality parameters after 180 DAS, i.e. seed germination (87.6%), seed viability (97.1%), seedling length (16.81 cm), SVI-I (1679.63) , seedling dry weight (131.31mg ), SVI-II (11536.3), seed moisture content (11.49 %) and seed infestation (8.56 %). Lowest result was observed in seeds T4-control (seeds sundried + stored in PP bag) with respect to seed germination (80.1%), seed viability (89.3%), seedling length (16.26 cm), SVI-I (1301.28), seedling dry weight (126.54 mg) and SVI-II (9371.9). However, in case of seed infestation, T2 (seeds dried in SBD + stored in poly-lined jute bag) was recorded the lowest with 17.67%. Therefore the findings revealed that seeds dried in SBD and stored in IRRI super bag can be an option for lesser seed deterioration of paddy seeds.ThesisItem Open Access INFLUENCE OF SEED FORTIFICATION ON GERMINATION AND EARLY SEEDLING VIGOUR OF CHILLI(2023) Borkakoty, Arkita; Deka, Sharmila DuttaIndia is one of the largest producers of chilli peppers with production of 1.98 million tonnes and contributes 43% of total spice export quantity of the country. Chilli belongs to the capsicum genus and encompass various species like Capsicum annuum, Capsicum chinense , Capsicum frutescens , Capsicum baccatum, Capsicum pubescens .There are thousands of chilli varieties worldwide varying in their characters. The main barrier to chilli production is prolonged and uneven germination. There are several methods that can be used to address the poor germination of chillies, and one of them is priming. Seed priming is the technique of carefully hydrating seeds to a point where pre-germination metabolic activity can continue but radicle emergence is prevented. An investigation was conducted in the laboratory of Seed Science and Technology Programme, Department of Plant Breeding and Genetics, Assam Agricultural University, Jorhat, Assam during the year 2022-2023.The pre-sowing seed treatments comprised of T1-untreated control,T2-hydropriming for 24 hours,T3-KNO3 priming @1% for 12hrs, T4-KNO3 priming @1% for 24hrs, T5-KNO3 priming @1.5% for 12hrs, T6-KNO3 priming @1.5% for 24hrs , T7-KNO3 priming @2% for 12hrs, T8-KNO3 priming @2% for 24hrs . All the priming treatments had significant effect on germination, and seed vigour characters .The seed germination parameters viz. germination percentage, days to germinate, germination index ,mean germination time, seedling length, seed vigour index-I, seed vigour index-II, seedling dry weight responded well in T3 in king chilli and capsicum variety Pongal-2and T5 in chilli variety Tez. .Seed cubes were prepared using a combination of soil, sand, saw-dust, coco-peat, vermicompost and cowdung (1:0.5:1:0.5:1:0.25) with 230-250ml of water per kg of medium and then shade dried for 36 hours. In the seed fortification procedure, primed seeds in the seed cubes were found best among all the other treatments for germination and seed vigour characters. It was observed that primed seeds in the cubes performed more efficiently in increasing the germination parameters than the unprimed seeds in the cubes.ThesisItem Open Access EFFECT OF SEED ENHANCEMENT ON SEED ESTABLISHMENT, SEED YIELD AND QUALITY OF DIRECT SEEDED RICE(AAU, Jorhat, 2019-07) BAISHYA, HIMASHRI; Borah, PrakashAn experiment was conducted during the kharif season of 2018 at Instruction cum Research Farm, Assam Agricultural University, Jorhat in split plot design with two seed rates in main plots and ten seed enhancement treatments in subplots replicated thrice. The seed enhancement treatments were also evaluated under laboratory conditions to study their effect on seed quality. All the characters in the laboratory evaluation, namely, speed of germination, seedling height, root length and seedling dry weight varied significantly except for the germination %. Results from the field experiment revealed significant variation among the treatments for all the characters, namely, field emergence (%), seedling height (cm), root length (cm), number of effective tillers, number of seeds/panicle, spikelet fertility (%), 100 seed weight (g), disease incidence (%) and seed yield (kg/ha) except days to 50% flowering. Interaction of the treatments with seed rates was significant for field emergence, seedling height, number of effective tillers, spikelet fertility and seed yield. The yield contributing characters, viz, number of effective tillers and spikelet fertility varied significantly under the two seed rates and showed better performance under the reduced seed rate than under the normal seed rate. Lower incidence of disease was recorded in respect of the treatments combinations with consortium of biocontrol agents (Trichoderma harzianum + Metarhizium anisopliae + Beauveria bassiana). Under both the seed rates, field emergence, seedling height, root length and seed yield showed better performance when treated with enhancements treatments along with a consortium of bio-control agents than those seeds which were treated with the enhancement treatments alone. The seed yield didn’t differ significantly between the two seed rates treatments. Hence, the results indicated that seed rate can be reduced to 56.25 kg/ha (75% of the recommended seed rate) without sacrificing performance in seed yield. Amongst all the treatments, Treatment 9 i.e. Ascorbate priming + Seed treatment with consortium of bio-control agents showed high values for the characters namely field emergence, 100 seed weight and seed yield with respect to the control. Disease incidence was also found to be the lowest in this treatment. Correlation studies revealed that the field emergence (%), number of effective tillers and number of seeds/panicle are significantly and positively correlated with seed yield (kg/ha), thereby indicating the importance of these characters in governing seed yield.ThesisItem Open Access APPLICATION OF BIO PRIMING FOR SEED INVIGOURATION AND EARLY SEEDLING ESTABLISHMENT(AAU, Jorhat, 2019-07) PEGU, PRITHVIRAJ; Deka, Sharmila DuttaRice is the world’s most important crop and is a staple food for more than half of the world’s population. Worldwide, rice is grown on 161 million hectares, with an annual production of about 744.4 million tons of paddy (FAO, 2014). Organic agriculture is a rapidly developing trend all around the world and more than 150 countries have adopted this technique and now produce organic food commercially. The most compelling reason for using organic seed when growing organic crops is that seed produced organically causes a less hazardous impact on the environment. Early crop establishment, lower productivity along with non- chemical disease management is a challenging task of seed technologist in organic seed production. Seed priming an effective seed invigoration method has become a common seed treatment to increase the rate and uniformity of emergence and crop establishment in most crops. Bio-priming is a process of a biological seed treatment that refers to the combination of seed priming and inoculation of seed with beneficial organism to protect the seed and improve the quality. In the present investigation, Beauverijal was found to be the best bio-agent for seed treatment as the results indicate better early seedling growth followed by higher no. of seeds/panicle and seed yield and less disease infestation. Early plant development and physiological functions could be impacted by early root growth reduction of disease incidence may also result in better yield performance. Commercial bio-agents viz. Trichojal and Metajal were also found to be effective in lowering the disease incidence and increase in seedling vigour followed by better yield performance. Comparative performance of cold adaptive PGPB (Trichoderma spp. + Bacillus spp.), Microbial consortium (C4) (Bacillus spp. + Pseudomonas spp.), Microbial consortium (C7, Bacillus spp. + Pseudomonas spp.), although designated as cold adaptive strains but does not impart any significant influence in enhancing seed vigour and early seedling growth. The colonization of the microbial agents in the rhizosphere region signifies its role in nutrient absorption and imparting abiotic stress resistance. The better adaptability of local commercial bio-agents in Trichojal, Metajal, and Beauverijal may lead to better performance in seed vigour, early seedling growth and final seed production.ThesisItem Open Access IDENTIFICATION OF MORPHO-CHEMICAL CHARACTERS FOR GENETIC PURITY TESTING OF RICE VARIETIES(AAU, Jorhat, 2019-07) KHANIKAR, MADHURYYA MOHAN; Sarmah, BhaswatiCharacterization of cultivars, establishment of varietal identity and genetic purity of the seed lots are crucial for varietal improvement, varietal protection and seed production. A rapid and reliable technique to verify the identity and to assess the purity of seed lots is important in seed quality assurance program. So, the present study was formulated to test 50 local varieties for genetic purity and group them based on the morphological similarities and response to various chemicals. The mean performance table of varieties based on quantitative traits revealed significant variation among the varieties for the quantitative traits. Based on the grain morphology, Black Rice (B), Nekeru and Pare were found to have long slender type of grain shape while Purubenu, Kola Konamasuri, Jeera Joha, Jengoni, Samraj, Vaboli Joha, Banki Sali, Basudev Bao and Bamkokua exhibited medium slender grain shape and Black Rice (G), Malbhog and Til Bora on the other hand, depicted basmati type grain shape. These three categories are highly preferred by the consumers due to its pleasant appearance. On the basis of chemical test, Bao, Sokua Bao, Samraj & Boga Ahu exhibited unique red colouration in the NaOH test. As per the phenol & modified phenol test, unique black colour was exhibited by Purubenu, Maniki Madhuri Joha, Joha Big and Kola Amona. The cluster analysis based on grain morphology revealed 4 predominant clusters, while based on chemical data, 2 distinct groups were obtained. Cluster I of the chemical data comprised of only one variety i.e. Sokua Bao while cluster II contained all the other varieties. This cluster could be further divided into 2 sub-clusters. The sub-cluster 1 comprised of all the Joha varieties except Jeera Joha while the sub cluster 2 encompassed all the Bao and the Black rice varieties indicating the two distinct amylose ranges. The most similar varieties with regards to the amylose content were Bao (9) and Pare. 16 varieties out of the total 50 varieties were found to have unique characters based on the morphological, chemical and biochemical parameters. These varieties are - Purubenu, Maniki Madhuri Joha, Joha Big, Kola Amona, Pare, Malbhog, Nekeru, Til Bora, Sokua Bao, Bao (9), Samraj, Boga Ahu, Black rice (B) and Black rice (G).
