Association analysis of F2 generation in rice (Oryza sativa L.) under salinity condition
Rice occupies a pivotal place in the Indian agriculture and has been grown under diverse ecological conditions and gets exposed to different environmental stresses like drought, salinity and submergence. Development of rice varieties for salinity affected areas is emphasized on the improvement of rice yield potential in a specific environment. Information related to the relationship between yield and its components in the breeding programme particularly for salinity is very limited. Hence, the present investigation was carried out to study the correlation and path analysis in F2 generation derived from two crosses namely ADT 43 x FL478 (Cross 1) and Improved White Ponni x FL478 (Cross 2) were evaluated at a farmer’s field at Vedapatti village, Tuticorin district of Tamil Nadu which is a saline track. Another rice variety FL478 (IR 66946-3R-178-1-1, derived from crossing between Pokkali and IR 29), has been promoted as an improved donor for breeding programs, as it has a high level of seedling stage salinity tolerance and is photoperiod insensitive, shorter and ûowers earlier than the original Pokkali. FL478 also maintains a lower Na+/K+ ratio than both the parent lines (Gregorio et al. 2002). Based on its ability to tiller well and maintain high potassium content under salinity stress, FL478 appears to be a good candidate for salinity stress tolerance in rice, particularly at the vegetative stage of growth. In Vedapatti village of Tuticorin district, due to over-pumping of groundwater in the past several years, normal irrigation water has become saline water. Moreover, this village is considered as a hot spot area for the saline condition. Hence, the six generations developed through hybridization techniques were evaluated for salinity tolerance at Vedapatti village. The soil and water samples were collected from the field to analyze the EC and pH. The soil salinity and water quality in the experimental plot were 4.82 ECdSm-1 and 8.09 (pH) for soil and 4.78 ECdSm-1 and 8.19 (pH) for water respectively. From the present findings, it is clear that the characters viz., number of tillers per plant, number of productive tillers per plant, number of filled grains per panicle, total number of grains per panicle and spikelet fertility have to be given prime importance during selection since they expressed significant and positive correlation with single plant yield and also a positive inter-correlation among themselves. Therefore, selection for anyone of the above characters would bring in the simultaneous improvement of other traits and also finally resort to improve the grain yield under salinity condition. Path analysis also revealed that selection for the number of productive tillers per plant and the number of filled grains per panicle are to be given prior importance during selection since they had a positive correlation and high direct and indirect effect on grain yield under salinity condition in rice.
It is certified that:
- The corresponding author is fully responsible for any disputes arising due to the publication of his/her manuscript.
- The article has been seen by all the authors who are satisfied with its form and content.
- The sequence of names of authors in the by-line is as per their relative contribution to this experiment, giving due credit to all scientists who made notable contribution to it.
- All the authors fully understand that inclusion of any other co-authors or exclusion of any co-authors is not possible once the article has been submitted to the journal.
- The corresponding author takes full responsibility for this article.
- The address of the organization where the research was conducted is given.
- The article is exclusive for this journal, and the results reported here have not been sent (and will not be sent during its consideration by this journal) for publication in any other journal.
- Authors agree to abide by the objective comments of referees and do agree to modify the article into a short note as per the recommendation, for publication in the Electronic Journal of Plant Breeding.
- If published in Electronic Journal of Plant Breeding, the copyright of this article would vest with the Indian Society of Plant Breeders, who will have the right to enter into any agreement with any organization in India or abroad engaged in reprography, photocopying, storage and dissemination of information contained in it, and neither we nor our legal heirs will have any claims on royalty.