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999			_c27274 _d27274
003			OSt
005			20220927114742.0
008			140128s9999 xx 000 0 und d
082			_a630.28 _bKUR/HE
100			_aKuriakose K P
245			_aHeterosis Breeding and In Vitro Mutagenesis in Pineapple(Ananas comosus[L] Merr.)
260			_aVellanikkara _bDepartment of Plant Breeding and Genetics, College of Horticulture _c2004
502			_bPhD
520	3		_aA study entitled" Heterosis breeding and in vitro mutagenesis in pineapple (Ananas comosus [L] Merr.) was undertaken in the Department of Plant Breeding & Genetics, College of Horticulture, Vellanikkara during 1998-2003. The main objective of the study was to create wide genetic variability for selecting ideal pineapple genotypes. The field studies were taken up at Pineapple Research Station, Vazhakulam. The six parental genotypes, used for hybridization, differ significantly in thirty four out of the thirty five growth, yield and quality characters studied. The genotypes also differ in qualitative characters like colour of leaf and fruit, depth of eyes and spine character. All the genotypes are having a few, not all, desirable characters. The genotypes differ significantly in number of flowers opened per day and number of flowers per inflorescence. The flowers of Mauritius, Kew, Selection-l and Ripley Queen open during 4 am to 5 am and that of Pampakuda local and Kakkoor local open during 5 am to 6 am. Flower opening and anther dehiscence coincides in all the genotypes. In all the genotypes, stigma remained receptive from 3 am to 6 pm. All the six genotypes were crossed in all possible combinations. The crosses K x S-] and M x RQ and their reciprocals were incompatible. The other crosses differ in the extend of cross compatibility. The genotype Mauritius expressed highest compatibility as a pistillate parent with all other genotypes. Among all cross combinations, Mauritius and PKDA are the most compatible parents. Out of the thirty cross combinations, only sixteen cross combinations reached the final stage of evaluation of the progenies. The highest survival of the seedlings was observed in PKDA x S-I. The hybrids in the sixteen cross combinations were evaluated individually for thirty five growth and yield characters using the parameters mean, range) percentage of variation of range over mean, mode, mean deviation from mode and coefficient of dispersion. Further, multivariate analysis using five characters, viz., fruit weight without crown, TSS, total sugar, juice weight % and pulp weight % was done by estimating the determinant of the eo variance matrix, Principal Component Analysis and Euclidean distance. All the characters expressed transgressive and independent segregation. Thus each individual plant is unique due to the independent segregation of each character. Evaluation of all the hybrids in all the cross combinations based on five selected characters, viz., fruit weight without crown, TSS, total sugar, pulp weight % and juice weight % simultaneously for relative heterosis, heterobeltiosis and standard heterosis resulted in identifying 13 hybrids with relative heterosis and 7 hybrids with standard, heterosis. When all.the twenty hybrids were compared, the hybrid number 257 of the cross M x K was having the highest heterosis in four out of the five characters. Among the progenies, hybrids with several distinct or abnormal features were observed. Albino seedlings were observed in 16 cross combinations. Hybrids with dual feature, low chlorophyll content, piping character, segregation of colour of heart at the time of initiation of inflorescence, creamy white heart, white flower, extra long and cylindrical fruit and fruits that ripen uniformly were obtained from among various crosses. For in vitro mutagenesis, shoot tips of Mauritius variety were cultured in MS medium supplemented with BAP and uniform masses of globular structures were irradiated with gamma rays at seven doses and compared with control. Chlorophyll , mutants and chimera were observed among the in vitro plants. Observations on height and number ofleaves at 30 days interval of growth up to 120 days from plant out stage showed that radiation of in vitro culture at 30 Gy gave enhanced vigour in growth of plantlets. The production of chlorophyll mutants, leaf chimera and variability in height and number of leaves indicated that in vitro mutagenesis could be used as a tool for creating genetic variability in pineapple.
700			_aPushkaran K (Guide)
856			_uhttp://krishikosh.egranth.ac.in/handle/1/5810015019
942			_2ddc _cTH