Browsing by Author "CHANNAPURAPU SAI RATNA SHARAVANI"
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ThesisItem Unknown STUDIES ON MUTAGENIC EFFECT OF GAMMA IRRADIATION IN TUBEROSE (Polianthes tuberosa L.)(COLLEGE OF HORTICULTURE, ANANTHARAJUPETA, KADAPA – 516105 ANDHRA PRADESH, 2019-11-07) CHANNAPURAPU SAI RATNA SHARAVANI; DR. K. SWARAJYA LAKSHMITuberose (Polianthes tuberosa L.) is a vegetatively propagated crop used as loose flowers, cut flowers and also as raw material for the extraction of the highly valued natural flower oil. Genetic improvement of tuberose is hampered by meager genetic variability, self incompatibility, seed sterility and these factors impair the conventional improvement programme. Mutation breeding is one of the best options for supersizing the genetic base and enhancing the crop diversity. Hence the present experiment entitled “Studies on mutagenic effects of gamma irradiation in tuberose (Polianthes tuberosa L.)” was carried at Floriculture block, College of Horticulture, Anantharajupeta, Y.S.R. Kadapa District, Andhra Pradesh during 2017-19 with the objective to estimate the lethal dose of physical mutagen, gamma rays, to evaluate the growth, yield and qualitative traits of tuberose cv. ‘Hyderabad Single’, subjected to gamma irradiation at LD50 (20 Gy) and to conduct molecular analysis of desirable mutants obtained from mutant population with RAPD and ISSR markers. The bulbs of tuberose cv. ‘Hyderabad Single’ were treated with different doses of gamma rays viz., 5 Gy, 10 Gy, 15 Gy, 20 Gy, 25 Gy and 30Gy at BARC, Mumbai. Untreated bulbs were used as control and the experiment was laid out in a CRD. The sprouting percentage decreased with gradual increase in dose of irradiation. The plant height was maximum in 5 Gy (44.8 cm), as the gamma irradiation dose increased all vegetative (survival per cent, plant height, plant spread, leaf area, width of leaves, number of shoots per clump), floral (spike length, rachis length, number of florets per spike, weight of floret, number of spikes per plant and flower yield), bulb (number of bulbs per clump, weight of bulbs, average diameter of bulbs, average length of bulbs and circumference of clump) and biochemical characters (SPAD chlorophyll content) recorded a gradual decline. The irradiation doses higher than 20 Gy recorded no flowering through out the period of study. Leaf variegation was observed for plants treated with 15, 20 and 25 Gy. The LD50 value was assessed based on mortality percentage and the probit analysis revealed that the LD50 value was 20 Gy. Subsequently, a total of 500 bulbs were treated with LD50 (20 Gy) value at BARC, Mumbai. The results indicated that, the growth, yield and quality parameters of some irradiated plants at LD50 value (20 Gy) showed superiority over control. Out of 265 mutants, 88 mutants were superior to control with regards to days to sprouting, 35 mutants were superior to control with regards to plant height, 35 mutants were found superior for leaf length, 21 mutants were found superior interms of leaf width, four mutants were found superior for number of shoots per clump, two mutants showed variegated leaves (M185 and M243) and 34 mutants with respect to number of primary branches. Among 265 mutants 69 mutants showed flowering. Among the floral components the mutants exhibited a superiority in the characters viz., early spike emergence (3 mutants), days to first floret opening (2 mutants), spike length (11 mutants), rachis length (6 mutants), number of florets (8 mutants), weight of floret (2 mutants), length of floret (23 mutants), perianth tube diameter (29 mutants), number of spikes per plant (1 mutant) and flower yield per plant (3 mutants) compared to control. Among 265 mutants, 5 mutants showed more number of bulbs per clump and weight of bulbs per clump, 45 mutants recorded maximum average diameter of bulb, 14 mutants recorded maximum average length of clump and four mutants recored maximum circumference of clump. Seventeen mutants were recorded superior for SPAD chlorophyll content and 180 mutants recorded superior for per cent disease index of Alternaria leaf spot compared to control. Wide spectrum of variation was observed in M1V1 generation for leaf colour. M185 had showed yellowish green (151C) at centre and green (137 A) at perifery, while, M243 showed green (138B) at centre with yellowish green (151C) at perifery. All the mutant population including control bore white colour flowers. There was a positive correlation among majority of the significant estimates, for flower yield per plant. Maximum positive correlation was recorded for number of florets per spike with flower yield, while minimum positive correlation was recorded for circumference of clump with flower yield per plant. Among the 113 significant correlations, 99 showed a positive trend, this correlation suggests that the improvement of those individual traits would simultaneously improve other pair wise traits due to correlated response. Traits which are significant with the flower yield per plant will also be useful in selection of desirable plants from the mutant population. From the mutant population molecular analysis was conducted for seven mutant plants, M2 (mutant plant showing compact floret arrangement and more number of florets), M 185 and M243 (Chlorophyll mutants), M308 (Dwarf statured mutant) M349, M395, M398 (branched inflorescence mutant) with 25 RAPD and 29 ISSR primers, which enabled to know the diversity among mutants and control. Maximum PIC, He, Ho, EMR and Rp registered with the RAPD and ISSR primers prompts insight of molecular complexity involved. Mutant population showing novelity, superiority in quality and yield were selected for progressing them to the next generation. The mutants M2, M50, M63, M83, M120, M185, M212, M243, M308, M319, M336, M337, M349, M395, M398, M436, M490 showed superiority in yield and quality traits. Hence, these mutant plants have been selected for progressing to M2 generationThesisItem Open Access STUDIES ON NUTRITIONAL DISORDERS OF GERBERA (Gerbera jamesonii L.)(College of Horticulture, Rajendranagar, HYD-30, 2016-07-23) CHANNAPURAPU SAI RATNA SHARAVANI; DR. B. NEERAJA PRABHAKARThe present investigation entitled “ studies on nutritional disorders of Gerbera (Gerbera jamesonii L.) was carried out in Floricultural Research Institute, A.R.I, Rajendranagar, Hyderabad during the year 2015-16 using hydroponics under shade net to develop and describe the nutrient deficiency symptoms of N, P, K , Ca, Mg, S, Mn, B, Fe, Zn and Cu. The experiment was conducted in CRD with 12 treatments and three replications. The influence of different nutrients on the growth, dry matter production, nutrient content and uptake were also recorded. Plants of Gerbera var. Savannah were grown with complete modified Hoagland solution and nutrient deficiency treatments were induced with a complete nutrient formula minus one of the nutrients.Withholding of different nutrients from the nutrient medium resulted in characteristic visual symptoms on foliage and growth of Gerbera plants. Nitrogen deficiency appeared at 21 DAT which resulted in yellowing of older leaves, P deficiency symptoms appeared at 30 DAT and deficiency resulted in dark green leaves and highly affected root system where in tap root was elongated. The K deficiency symptoms appeared at 30 DAT which appeared as tannish brown necrosis along the margins of older leaves. Calcium starved plants expressed deficiency symptoms in younger leaves at 25 DAT which resulted in leathery, brittle and pale green colour with whitish spots. Symptoms of Mg deficiency appeared at 32 DAT which was exhibited as intervienal chlorosis on older leaves. Sulphur deficiency symptoms appeared at 40 DAT and showed uniform chlorosis on younger leaves. Among micronutrients, plants grown in Mn deficient treatment did not express visual deficiency symptoms. Boron deficiency symptoms resulted in marginal necrosis of leaf apex on newly emerging leaves at 21 DAT. Iron deficiency symptoms appeared at 40 DAT as intervienal chlorosis on younger leaves. Zinc deficient plants expressed symptoms at 35 DAT which showed intervienal chlorosis on older leaves. Copper deficiency symptoms appeared at 20 DAT which resulted in distorted young leaves. Gerbera plants grown in different nutrient deficient solutions showed reduced plant growth when compared to plants supplied with complete nutrient solution. Nitrogen deficiency significantly influenced the growth parameters and resulted in reduced plant height, leaf number plant-1, leaf area, root length, dry weight of shoot and root & shoot/root ratio. Besides, minimum SLW and maximum SLA were recorded. Plants grown in complete nutrient solution recorded maximum values for most growth parameters. However, SLA was low in plants grown in complete nutrient solution whereas, shoot/root ratio recorded maximum in Fe deficient solution. Leaf analysis revealed that in deficiency situation, content of individual mineral element was reduced. Some interactions between nutrients also showed up. Nitrogen content was enhanced in K deficient treatment, P content in Zn deficient treatment, K, Ca and Mn content in Mg deficient treatment, Mg content in K deficient treatment, S content in N deficient treatment, B content in Ca deficient treatment, Fe content in Cu deficient treatment, Zn content in Fe deficient treatment and Cu content in Fe deficient treatment were increased. The nutrient uptake was recorded at the end of experiment and plants grown in complete nutrient solution recorded maximum uptake of all macro (except P & Ca) and micronutrients (except Fe & Cu). The treatment without Zn recorded higher uptake of P, similarly higher uptake of Ca in B deficient treatment, Fe in Cu & Mn deficient treatments, Cu in Zn deficient treatment. In general uptake of different mineral elements in leaves of Gerbera plants was directly proportional to the amount of growth put forth under different nutrient deficiencies. In the present study, without N and without Cu treatments showed early symptoms (21 and 20 DAT respectively). Plant growth was greatly reduced by N deficiency followed by P, K, Ca and Fe. Whereas, treatment without Mn did not resulted in any visual symptoms during the period of study (60 DAT).