PG Thesis

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    Integrating weed management with nano nitrogen in okra(Abelmoschus esculentus(L.) moench)
    (Department of agronomy, college of agriculture, Vellayani, 2023-09-21) Navaneetha, C; Ameena, M
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    Assesment of multiple abiotic stress tolerance mechanisms in rice (Oryza sativa L.)
    (Department of Plant Biotechnology, College of Agriculture,Vellayani, 2019) Alif Ali, B S; Beena, R
    The study entitled “Assessment of multiple abiotic stress tolerance mechanisms in rice (Oryza sativa L.)” undertaken at the Department of Plant Physiology, College of Agriculture, Vellayani during 2018-19. The objective was to study the multiple abiotic viz. drought, salinity and high temperature stress tolerance mechanisms in rice and to validate the identified QTLs for stress tolerance in rice. The investigation comprises four experiments, In experiment I initial screening of 20 rice genotypes for single abiotic stress tolerance was studied. Stresses were induced using different concentrations of PEG6000, NaCl and temperature controlled incubator for providing drought, salinity and temperature stresses respectively. Germination study was carried out using paper towel method. In the first experiment drought stress were given at concentrations -1bar, -3bar, 5bar and -7bar water potentials of PEG6000, salinity stress was given at 100mM, 150mM, 200mM, 250mM NaCl and temperature stress were given at 350C, 400C, 450C and 500C for all 20 rice varieties with two replications. The physio-morphological and biochemical parameters were studied on 14th day of germination. The highest level drought, salinity and temperature stresses at which germination occurred was selected as Dh (-5 bar), Sh (250mM NaCl) and temperature (Th) (350C) respectively. Among 20 rice varieties, PTB-7, PTB-60 and PTB-35 showed maximum seedling vigour at highest level of drought stress (Dh) stress condition Vyttila-9, MO-18 and Vyttila-3 recorded maximum seedling vigour index at highest tolerated level of salinity (Sh) stress condition and N-22, NL-44 and Vyttila -6 showed maximum seedling vigour index at highest tolerated level of temperature stress (Th) stress condition. These nine genotypes were selected for the evaluation of combination stress treatment In the second experiment, The combination stress treatments given were Dh x Sh, Dh x Th, Th x Sh and Dh x Sh x Th. Rice varieties did not germinated at Dh x Sh and Dh x Th. The maximum seedling vigour index at Dh x Sh and combination stress treatment was observed in PTB-7, Vyttila-9, PTB-35 and at Th x Sh was observed in NL-44, MO-18 and N-22 respectively. These rice varieties were selected as tolerant varieties. In experiment III six rice varieties selected from combination stress treatment were evaluated for yield parameters in pot culture experiment. The design of the experiment was CRD with two replications and one control. Drought and salt stress were imposed during reproductive stage for 5 days by applying -5bar PEG6000 and 250mM NaCl solutions respectively into the pots containing rice varieties, Temperature stress was induced using a temperature controlled polyhouse from panicle initiation to maturity stage. Physio-morphological, biochemical and yield parameters were studied under the combination stress treatments. Highest yield under the combination stress treatment of Dh x Sh was observed in PTB-7 and highest yield under the combination stress treatment Th x Sh was observed in N-22. Based on morpho-physiological and yield parameters PTB-7 was selected as the tolerant variety under drought and saline condition and N-22 was selected as the tolerant variety under temperature and salinity condition. In experiment IV all the 20 genotypes were analyzed for the identification of reported markers linked to stress tolerance such as drought salinity and temperature. Reported microsatellite markers linked to drought, salinity and temperature were used to screen 20 rice varieties. Among the markers distinct polymorphism for temperature tolerance between temperature tolerant (N-22 and NL-44) and susceptible varieties was shown by RM 6100. RM 7076 showed distinct polymorphism in tolerant varieties PTB-7 and NL-44 . RM 1287 showed distinct polymorphism for salinity tolerance in PTB-7 and N-22. Drought tolerance between drought tolerant (PTB-7) and susceptible varieties was Shown by RM 490.
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    Marker assisted backcrops breeding in rice for drought tolerance
    (Centre for Plant Biotechnology and Molecular Biology, College of Horticulture, Vellanikkara, 2019) Athulya S Nair; Abida, P S
    Rice {0ryza sativa L.) is one of the most important food crop grown across the globe. The crop is cultivated in diverse environments ranging from uplands to deep water ecosystems. Drought is one of the major constraints for rice production in rainfed lowlands. In the present scenario of climate change, the frequency of drought is more likely to increase in the future, making drought resistance in rice varieties indispensable. During the era of post-green revolution, many locally adapted traditional rice varieties (TRVs) were replaced by high yielding varieties (HYVs) that thrive best in the irrigated ecosystem. Most of these HYVs sutTer heavy yield loss even under mild water deficit conditions. Hence, improving drought tolerance of high yielding varieties is imperative. Considering this, the study 'Marker assisted backcross breeding in rice for drought tolerance,' was executed with an objective to improve drought tolerance in high yielding rice variety Ptb 39 (Jyothi; J) using Ptb 30 (Chuvannamodan; Ch) as donor parent, through marker assisted backcross breeding. Jyothi is a popular high yielding rice variety of Kerala derived from the cross between Ptb 10 and IR 8. Chuvannamodan is an improved landrace, recommended for ''Modan^ i.e., upland cultivation owing to its drought tolerance ability. Morphological characterisation of both the varieties was done at Regional Agricultural Research Station, Pattambi, during 2018. Chuvannamodan registered a higher vegetative growth than variety Jyothi. The plant height and the number of productive tillers were 141 cm and 33 respectively in Chuvannamodan, while, in comparison, it was 91 cm and 17 in Jyothi. It was also observed that Chuvannamodan flowered earlier (Days to 50% flowering: 76 days) than variety Jyothi (Days to 50% flowering: 93 days). However, Jyothi out-performed Chuvannamodan with respect to the yield traits like number of filled grains per panicle (Ch: 71 and J: 104), iOOO-grain weight (Ch: 27.00 g and J: 28.30 g), and grain density (Ch: 1.09 g/cm^ and J: 1.11 g/cm^). The sterility in Chuvannamodan and Jyothi was 11.40 per cent and 18.40 per cent respectively. The water mining traits like root length, root volume, root dry weight and root to shoot ratio were higher in variety Chuvannamodan. The root length, root volume, root dry weight and root to shoot ratio of Chuvannamodan was respectively 109cm, 96cm"\ 31.60g and 0.31, while, it was 68cm. 32cm^,14.40g and 0.24 respectively in variety Jyothi. The genetic polymorphism study between Jyothi and Chuvannamodan was I studied using 120 SSR markers. Forty-seven markers were found to be n, polymorphic between the two genotypes. Among these polymorphic markers, 24 are reported to be linked to drought tolerance traits. Forty five F1 seeds were obtained by hybridizing variety Jyothi (as female parent) and Chuvannamodan (as male parent). Staggered sowing of the two varieties was done at weekly intervals for this purpose. Only six Fj seeds germinated. The test for confirmation of hybridity was conducted in these plants along with the parents. The polymorphic markers RM3825 and RM263, which are reported to be linked to drought traits were used for hybridity testing. Two plants, P5 (Plant No.5) and P6 (Plant No.6), were confirmed to be true hybrids as they were found to be heterozygous for the parental alleles. The hybrids (P5 and P6), were then backcrossed to the recurrent parent Jyothi to produce BCiFi seeds (15 Nos.). Simultaneously, selfing of the Fis to generate F2S (300 Nos.) was also done. In order to advance further the marker assisted backcross breeding programme aimed at imparting drought tolerance to Jyothi, the BC1F1s produced need to be genotyped further to identify progenies with resistant alleles for drought tolerance. The F? population can be forwarded to develop RJLs (Recombinant inbred lines) that would enable mapping of qualitative traits and quantitative trait loci related to drought tolerance. The F2S can also serve as the base population for the development of advanced breeding lines through pedigree selection.
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    Media improvement for in Vitro culturing and hardening of TC Banana CV. Nendran
    (Department of Pomology, College of Agriculture, Padannakkad, 2019) Vinayak Lamani; Meera Manjusha, A V
    The research work “Media improvement for in vitro culturing and hardening of tissue culture banana cv. Nendran” was carried out 1) to study the effect of nitrogen sources (ammonium and nitrate) on shoot and root regeneration in tissue cultured Nendran banana and 2) to standardize methods to enhance the growth and survival of plantlets during primary and secondary hardening stage. Experiments were conducted at the Regional Agricultural Research Station, Pilicode, Kasargod during 2017-2019. First experiment consisted of in vitro culture with five treatments- T1 – MS media (control) (NH4NO3 1650mg/l and KNO31900mg/l), T2 - Modified MS media (2850mg/l KNO3 + 825mg/l NH4NO3), T3 - Modified MS media (1900mg/l KNO3), T4 -Modified MS media (3800mg/l KNO3) and T5 - Modified MS media (1900mg/l KNO3 + 1361mg/l (NH4)2H2PO4). In the first experiment, normal MS media T1 (control) was observed to be superior one compared with other treatments (modified MS media). It recorded maximum number of multiple shoots per explant after 4th, 5th and 6th subculture and highest shoot length, number of leaves, number of roots, root length and maximum fresh and dry weight of shoot after the rooting stage. Second experiment on primary hardening was carried out with nine treatments such as T1- sand (control), T2 - coco peat, T3 - vermicompost, T4 - sand + coco peat (1:1), T5 - sand + vermicompost (1:1), T6 - coco peat + vermicompost (1:1), T7 - sand + coco peat + vermicompost (1:1:1), T8 - sand + coco peat + vermicompost (1:2:1) and T9 - sand + coco peat + vermicompost (1:1:2) . Primary hardening study was carried out with different hardening media. Plant growth and survival were effectively influenced by hardening media. T1, T2, T6, T7 and T9 showed 100 percent survival but T3 (47.33 %) and T5 (18.00 %) had lower survival rates. With respect to various growth parameters T6 recorded highest 117 plant height, pseudostem girth, number of leaves, leaf length, leaf width, leaf area, root length and highest shoot fresh and dry weight and T2 had recorded maximum number primary and secondary roots and root weight which was on par with T6. Third experiment on biotization was done with nine treatments consisting of T1 - Arbuscular mycorrhizal fungi, T2 - Azotobacter, T3 - Azospirillum, T4 - PSB (Pseudomonas fluorescens), T5 - AMF + Azotobacter, T6 - AMF + Azospirillum T7 - PSB + Azotobacter, T8 - PSB + Azospirillum and T9 - Control (Potting mixture only). Investigation on biotization of plants, revealed significant effects on plant growth and development through enhanced nutrients uptake. All treatments showed 100 % survival. Among treatments, T8 recorded highest plant height at 30 and 60 DAT, maximum pseudostem girth was found in T1 and T6 at 30 and 60 DAT. With respect all leaf characters T7 was significantly superior which recorded maximum leaf length, leaf width and leaf area at both stages. T5 recorded more number primary and secondary roots, primary root length and root weight and shoot fresh and dry weight compared to control. Chlorophyll content was maximum in T7 and T4 at 30 and 60 DAT respectively. In the nutrient status of plants, T1 recorded maximum content of P and K and N content was more in T3. Plants of T5 recorded highest uptake of Zn, Fe and Mn. Cu and B content were more in T7 and T1 respectively. For successful in vitro culture of banana cv. Nendran, both ammoniacal nitrogen and nitrate nitrogen are required as per the results obtained. For successful transplantation of tissue cultured plants, acclimatization is an integral process in tissue culture technique, which involves primary and secondary hardening. For primary hardening, T6 - mixture of coco peat and vermicompost (1:1) was the best for successful survival and growth of plantlets. Biotization was found to be an important technique in secondary hardening stage, which enhanced the growth and development of plants through increased uptake of nutrients from media. Among the treatments, T5 - AMF and Azotobacter combination was the best for secondary hardening.
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    Identification of saline tolerant rice hybrids for pokkali tract
    (Department of Plant Breeding and Genetics, Vellanikkara, 2019) Nikhil Narayanan; Biju, S
    Various abiotic stresses causing a decline in global rice production are drought, salinity and chillness. Among these, salinity is the major factor that affects crop productivity. The traditional rice varieties grown under Pokkali area show remarkable tolerance to salinity and floods making it unique. However, the yield potential of these varieties is low. In India, out of ninety three rice hybrids developed, a few viz. DRRH 28, KRH 4, PSD 3, etc. were reported to have tolerance to salinity. Considering the potentials of hybrids, identification of salt tolerant hybrids suitable for Pokkali tract of Kerala is an urgent need of the hour. Hence, the study was designed to explore the adaptability of eight rice hybrids to the unique tract of Pokkali and evaluation of traits associated with salinity tolerance. The study comprised of two experiments, the first experiment was Laboratory screening for salinity tolerance and the second experiment was Field evaluation of rice hybrids in Pokkali tract. The laboratory screening was done following a completely randomised design and the genotypes were grown in Yoshida's solution and evaluated for various seedling characters. High shoot length, root length, high root CEC and high root and shoot proline content were seen in Vytilla-6 followed by Ezhome-2. Low root and shoot proline content were observed in IR-29 confirming its susceptibility to salinity. Among the hybrids, a high value for shoot length, root length, total number of roots, root CEC, root proline, shoot proline and survival per cent was observed in the hybrids CORH-3 and KRH-4. Vigour index was high in Sahyadri 4 followed by KRH-4 and low in MRP- 5401. Vytilla-6 and Ezhome-2 showed the high survival per cent while low survival per cent was noticed in Sahyadri 2 and MRP-5401. Vytilla-6 exhibited high chlorophyll content and RWC while low RWC was recorded in MRP-5401, Sahyadri- 2 and Sahyadri-4. Ca in root and shoot along with Na content in shoot were high in IR-29 while Vytilla-6 had low Ca and Na content. High Na in root was seen in Sahyadri 4 followed by Sahyadri 3. High amount of root Cl2 was recorded in Sahyadri-3, Sahyadri-1, Sahyadri-4, IR-29 and Sahyadri-2 while, the lowest amount of root and shoot Cl2 was in Vytilla-6. High amount of shoot Cl2 was seen in Ezhome-2 and IR-29. High amount of root and shoot SO4 content was seen in IR-29, Sahyadri-3, Sahyadri-4, Sahyadri-2 and Sahyadri-1. The lowest root and shoot SO4 content was recorded in Ezhome-2, followed by Vytilla-6. Low visual score of 3 was recorded in Vytilla-6 and Ezhome-2; a score of 5 was recorded for CORH-3, MRP-5401, TNAU RH-4 and KRH-4. Sahyadri-2, Sahyadri-3 and Sahyadri-4 were observed to have scored more than seven. Score 9 was noticed in Sahyadri-1 and IR-29, indicating that these genotypes are more susceptible to salinity. Visual score under salinity was found to be negatively correlated with shoot and root length, number of roots, vigour, proline content and RWC, while it was positively correlated with content of Ca, Na, Cl2, SO4 and K in the plant tissue. Field evaluation of rice hybrids in Pokkali tract was done during Kharif season of 2016-17, following a randomised block design. Days to fifty per cent flowering and maturity showed that all hybrids became early under salinity. Tall plants were observed in Vyttila-6 and Ezhome-2 and short plants in IR-29. High number of productive tillers was observed in CORH-3 and low in Sahyadri-2. Ezhome-2, IR-29 and Vyttila-6 had high number of spikelets per panicle while seed setting percentage and long panicles were observed in Ezhome-2. Spikelet sterility was high in Sahyadri-2 and low Ezhome-2. High 1000 grain weight was observed in Ezhome-2 and low in IR-29. Based on visual scoring Vyttila-6 was classified as highly tolerant and IR-29 as highly susceptible. Correlation studies indicated that grain yield per plant was positively correlated with productive tillers per plant and seed setting per cent, while it was found to be negatively correlated with sterility per cent. Visual scoring was negatively correlated with plant height, uppermost internodal length, days to maturity and seed setting per cent. The hybrid CORH-3 was found to be moderately tolerant based on visual scoring and it produced highest yield per plant indicating that this hybrid is better than saline tolerant traditional varieties.
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    Genetic evaluation of F2 generation for yield and water stress tolerence in upland rice
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2018) Ivy Mary Rajan; Lekha Rani, C
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    Salicylic acid mediated metabolite elicitation and growth responses in long pepper (Piper longum L.)
    (Department of plantation crops and spices, college of agriculture, Vellayani, 2019) Krishna Veni Harish; Deepa S Nair
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    Chitosan mediated metabolite elicitation and growth responses in kasthuri turmeric(curcuma aromatica)
    (Department of plantation crops and spices, college of agriculture, Vellayani, 2019) Nivya J Thengumpally; Deepa S Nair
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    Irrigation scheduling and live mulching in upland rice (Oryza sativa L.)
    (Department of Agronomy, College of Horticulture, Vellayani, 2018) Aparna, R A; Jayakrishnakumar, V
    The experiment entitled ‘Irrigation scheduling and live mulching in upland rice (Oryza sativa L.)’ was undertaken at farmer’s field at Peringammala, Kalliyoor, Thiruvananthapuram during Virippu 2017 to standardize irrigation schedule for economizing water use and study the effect of live mulching with cowpea on growth and yield of upland rice. Prathyasa (MO 21) was used as the variety. The experiment was laid out with 14 treatment combinations involving seven irrigation treatments (I1 - irrigation at 3 cm depth at 10 mm CPE, I2 - irrigation at 3 cm depth at 20 mm CPE, I3 - irrigation at 3 cm depth at 30 mm CPE, I4 - irrigation at 2 cm depth at 10 mm CPE, I5 - irrigation at 2 cm depth at 20 mm CPE, I6 - irrigation at 2 cm depth at 30 mm CPE and I7 - rainfed control) and two mulching treatments (M1 - no live mulching, M2 – live mulching with cowpea) with three replications in randomized block design. The results revealed that I1 recorded the highest value for the growth characters viz., plant height at 60 DAS, tiller number m-2 at 60 DAS, LAI at 60 DAS and DMP at harvest. At harvest, the tallest plants were produced by I4. M2 registered the highest dry matter production at harvest. The interaction i1m2 recorded the highest tiller number m- 2 . The yield attributes and yield were significantly influenced by the irrigation treatments. The treatment I1 recorded the highest length of panicle, weight of panicle, number of filled grains panicle-1 and thousand grain weight. M2 produced the highest productive tillers m-2. I1 registered the highest grain yield (2949 kg ha-1), straw yield (3100 kg ha-1) and harvest index (0.49). The grain and straw yields were the highest for M2. The grain yield (3057 kg ha-1) was the highest for i1m2 and significantly superior to other treatments. It was noticed that I1 recorded the highest relative leaf water content and I7 registered the highest proline content. The uptake of N, P and K differed significantly. I1 and M2 recorded the highest NPK uptake. The interaction effect i1m2 registered the highest values for N and P uptake. The root characters viz., root volume, root dry weight and root shoot ratio were significantly increased due to irrigation and I1 recorded the highest values. The root length was the highest for I7. Among the mulches, M2 recorded the highest root length and root shoot ratio. The highest consumptive use was recorded by I1, M2 and their interaction i1m2. The highest water use efficiency (3.72 kg ha-1 mm-1) was recorded by I5 and was on par I3 and superior to other treatments. M2 registered the highest WUE (3.51 kg ha-1 mm-1) and superior to M1. The available N, P and K status were the highest for I7. The available soil N and K were the highest for M2. The interaction effect i7m2 registered the highest values for available soil N and K. The highest weed dry weight was recorded by I1, M1 and their interaction i1m1. The highest net income was obtained with I1 and was on par with I2 and I4. The highest BCR was recorded by I2 and was on par with I4 and I1. M2 recorded the highest net income and BCR. The interaction i1m2 recorded the highest net income and was on par with i4m2. The interaction i1m2 registered the highest BCR (1.46) and was on par with i2m1, i2m2, i4m2 and i5m2. The results revealed that frequent irrigation especially at 3 cm depth at 10 mm CPE in combination with live mulching of cowpea favourably influenced most of the growth, yield attributes, yield, physical, chemical properties of the soil and economics of cultivation. Although the highest grain yield was recorded by i1m2, it was found that i1m2 was on par with i4m2 for net income suggesting that irrigation at 2 cm depth at 10 mm CPE with live mulching of cowpea is as good as i1m2. For BCR, i1m2 was on par with i2m1 , i2m2 , i4m2 and i5m2 suggesting that irrigation at 2 cm depth at 20 mm CPE with live mulching of cowpea is as good as i1m2. For higher water use, irrigation at 2 cm depth at 20 mm CPE (I5) and live mulching of cowpea (M2) can be recommended. From farmer’s point of view, irrigation at 2 cm depth at 10 mm CPE with live mulching of cowpea is beneficial for higher economic returns in acute water deficit areas.
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    Magnesium sulphate fertilization for yield enhancement in direct seeded rice
    (Department of Agronomy, College of Agriculture, Vellayani, 2018) Daly George; Girija Devi, L