Thumbnail Image

Professor Jayashankar Telangana State Agricultural University, Hyderabad (Telangana State)

Browse

2006 - 200912020 - 20221
Reset filters
Thesis Type: Ph.D × Subject: Seed Science and Technology ×
Reset filters

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    ThesisItemOpen Access
    GENETIC PURITY ASSESSMENT OF MAIZE HYBRIDS USING MORPHOLOGICAL AND MICROSATELLITE MARKERS
    (PROFFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY, 2022-10-21) Neelothpala, M.; Jhansi Rani, K.
    Maize is one of the important cereal crops in which a large number of hybrids are developed. Testing the genetic purity of the hybrids is one of the important requirements for successful seed production. The present investigation entitled “Genetic purity assessment of maize hybrids using morphological and microsatellite markers” was undertaken to assess the genetic purity and to identify distinct morphological and microsatellite markers for the maize hybrids developed by PJTSAU. Four hybrids viz., DHM-117, DHM-121, KNMH-131 and KNMH-141 along with respective parental inbred lines viz., BML-6, BML-7, BML-45, PFSR-3 and KML-225 were selected for the present study. Morphological characterization was carried out through 26 DUS traits during kharif 2019 at six stages viz., beginning of anthesis, anthesis halfway, caryopsis watery ripe stage, medium milk stage, caryopsis hard stage and caryopsis loosened stage. Twenty five out of twenty-six traits have expressed variation among the hybrids and parental inbred lines. Row arrangement of kernels in the middle of the ear was straight in all of them and did not express any variation. Among the nine entries, specific DUS traits were identified for one hybrid viz., DHM-117 and four parental inbred lines viz., BML-7, BML 45, PFSR-3 and KML-225. Curved attitude in the lateral branches of tassel, absence of anthocyanin colouration of brace roots of stem and glumes of tassel excluding the base, presence of anthocyanin colouration of leaf sheath below the ear, cylindrical shape of the ear and medium placement of the ear were identified as specific DUS traits for DHM-117, KML 225, PFSR-3, BML-7 and BML-45 respectively. Name of the Author : M. NEELOTHPALA Title of the thesis : GENETIC PURITY ASSESSMENT OF MAIZE HYBRIDS USING MORPHOLOGICAL AND MICROSATELLITE MARKERS Degree : DOCTOR OF PHILOSOPHY Faculty : AGRICULTURE Discipline : SEED SCIENCE AND TECHNOLOGY Major Advisor : Dr. K. JHANSI RANI University : PROFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY, RAJENDRANAGAR, HYDERABAD-30 A total of 150 SSR primers distributed on all the 10 pairs of chromosomes of maize were used to conduct polymorphic survey among the parental inbred lines. Out of 150 SSR primers, 50 were found to be polymorphic among the five parental inbred lines where they generated a total number of 111 alleles with an average of 2.2 alleles per polymorphic primer pair and the average PIC value was 0.345. Out of 50 polymorphic SSR primers six of them were highly informative with PIC value above 0.50, thirty-seven markers were moderately informative with PIC value between 0.25-0.50 and seven were less informative with PIC values less than 0.25. Expected heterozygosity (He) ranged from 0.20 to 0.80 with a mean value of 0.468 and observed heterozygosity (Ho) ranged from 0 to 1 with a mean value of 0.084. Out of 50 polymorphic SSR primers 11 SSR primers confirmed the purity of selected hybrids. SSR primers bnlg 1137, umc 1014, umc 1798 and umc 1822 confirmed the hybridity of DHM-117 and KNM-131. Primer bnlg 1185 has confirmed the hybridity of DHM-117, KNMH-131 and KNMH-141 and umc 2163 has confirmed the hybridity of DHM-117, DHM-121 and KNMH-141. Primer bnlg 2042 has confirmed the hybridity of DHM-117 and DHM-121. Primers bnlg 1138, bnlg 1914, umc 2208, bnlg 1175 confirmed the hybridity of DHM-117, KNMH-131, KNMH-141 and DHM-121 respectively and were identified as specific primers which differentiated that respective hybrid from the other three hybrids. The eleven SSR primers which confirmed the purity of hybrids were used to group four hybrids and five parental inbreds of maize using DARwin 6.0.21 which divided them into two major groups. Group I consisted of two hybrids viz., DHM-117 and DHM-121 and their female parental inbred lines BML-6 and BML-45 respectively and group II consisted of two hybrids viz., KNMH-131 and KNMH-141 and their female parental inbred lines PFSR-3 and KML-225 along with the common male parent BML-7. The results revealed that all the four hybrids were genetically more similar to their female parents than that of male parents. Correlation between the morphological and molecular data was worked out by extracting DNA from 36 plants individually and by screening with respective specific SSR markers identified for each of the hybrid. The offtypes detected using SSR marker profiles were verified with that of the contaminants in the field by comparing with DUS characters at all the stages of crop growth. In three hybrids viz., KNMH-141, KNMH-131 and DHM-121 eight plants have exhibited their respective female similar bands and twenty-eight plants have confirmed the hybridity by exhibiting both female and male alleles whereas in DHM-117 four plants have shown female similar bands and thirty-two plants have confirmed the hybridity. The plants which have shown female similar bands in the SSR profiles have also expressed the female specific DUS traits throughout the growing season. It can be concluded that SSR markers are potential tools for the genetic purity testing of the seed lots which can detect the selfed plants and off types at the seedling stage itself
  • Thumbnail Image
    ThesisItemOpen Access
    QUALITY HYBRID SEED PRODUCTION BY REGULATION OF SEX EXPRESSION IN CASTOR (Ricinus communis L.)
    (ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY, RAJENDRANAGAR, HYDERABAD, 2006) SUJATHA, v; ANKAIAH, R
    In the present investigation, the parental lines of DCH-177 hybrid i.e., DPC-9 (female line) and DCS-9 (male line) were sown at 3:1 ratio in three different dates. The seed parents, DPC-9 was studied in order to know the influence of environment (September, October, November sowings) and growth regulators on sex expression and hybrid seed quality. The experiment was taken up during rabi, 2005 at National Seed Project, Acharya N.G. Ranga Agricultural University, Rajendranagar, Hyderabad. The experiment was laid out in Randomised Block Design in three replications. The environment (dates of sowing) showed significant effect on sex expression. September 16th sowing recorded more number of pistillate plants with less number of interspersed staminate flowers followed by October 16th sowing, whereas sowings done in November had very little influence on sex expression with less number of pistillate plants/plot. Ethrel treatment enhanced the expression of pistillate flowers by suppression of interspersed staminate flowers while reverse was true with the GA3 which promoted ISF. October sown crop recorded higher plant height, 100 seed weight and length of primary spike as compared to November and September sown crops. November sown crop recorded early flowering and early maturity when compared with September and October sowings while September sown crop recorded maximum seed yield which was significantly superior to November and October sowings. Ethrel treatment recorded minimum plant height however recorded maximum spike length, 100 weed weight and maximum seed yield while GA3 treatment recorded maximum plant height and early maturity. Seed quality parameters like germination per cent, seedling vigour index and field emergence index were recorded high in the seed obtained from September and October sowings as compared to November sowing. Hybrid seed obtained from September and October sown crops recorded high genetic purity and it was above certification standard (>85%) while seed obtained from November sown crop had very low genetic purity and it was below certification standard. Ethrel treatment enhanced the quality of the seed quality parameters as compared to GA3 treatment, water spray and control. Manual removal of ISF in seed parent during seed production resulted in higher genetic purity (95.9 %) and it was on par with Ethrel treatment (94.0-96.2%). Ethrel treatment resulted in high genetic purity of hybrid seed due to suppression of ISF and maintenance of stable pistillate plants, while seed obtained from GA3 sprayed plots recorded very low genetic purity (70.1-78.8%) as a result of more number of ISF in seed parent. It was concluded that September and October sowings were congenial for quality hybrid seed production. Ethral @ 0.1% was found very effective for obtaining better quality seed by suppression of ISF in seed parent.