Chand, UttamSharma, Prashant2022-02-102022-02-102021-07-09https://krishikosh.egranth.ac.in/handle/1/5810182071The present investigation entitled “Line × tester analysis of yield and its contributing traits in maize (Zea mays L.) was conducted at Experiment Farm, Shivalik Agricultural Research and Extension Centre, Kangra during Kharif 2020 to study nature of gene action involved and estimation of heterosis and combining ability effects of yield and its contributing traits. Experimental material consisted of 25 lines, 2 testers and their 50 crosses along with standard checks viz., Palam Sankar Makka-2 and PSCL 4640 were evaluated using Randomized Block Design with two replication. Genotype mean square was significant for days to 50% tasseling, days to 50% silking, days to 75% brown husk, ear height (cm), plant height (cm), ear length (cm), ear circumference (cm), kernel rows/cob, kernels/row, 1000-kernel weight (g), shelling (%) and grain yield (q/ha) which indicated the presence of sufficient genetic variability in the material studied. Also the ratio of GCA variance to SCA variance was less than unity for all traits indicated preponderance of non-additive gene action. Based upon mean performance, L25 exhibited higher grain yield followed by L24 and L5. These lines also exhibited highest significant GCA effect for grain yield and were identified as promising parents. Among testers, T1 was good general combiner for ear length, ear circumference, kernel rows/cob, kernels/row, 1000-kernel weight, shelling (%) and grain yield, whereas, T2 was good general combiner for ear height and plant height. L25 × T1, L5 × T1, L4 × T1, L6 × T1 and L24 × T2 exhibited superior grain yield as compared to the best check, viz., Palam Sankar Makka-2. These crosses also exhibited maximum SCA effect and significant standard heterosis for most of traits. In addition, these crosses also showed moderately resistance to resistance disease reaction to MLB, TLB and BLSB under natural epiphytotic conditions. These promising cross combinations need to be evaluated in multi-location trials over the years to assess their suitability in different agro-climatic zones of the StateEnglishThesis