A doctoral thesis within the College of Agriculture

The doctoral thesis titled “Estimation of Genetic Markers for Growth and Yield Traits through Reciprocal Half-Diallel Crossing of Some Tomato Varieties under the Influence of Nano-sized Potassium Oxide Spray” was discussed at the College of Agriculture, University of Diyala, in the presence of the college dean, Professor Dr. Raed Khalil Ibrahim. The study presented by the student Jabbar Khalaf involved deriving individual hybrids by planting seeds from six pure lines (pi.Bee, Genetics J., B.B, Tas.ch, 21, and T150S), imported from the Tomato Genetic Resources Center at the University of California, Davis, USA, through Dr. Jafar Hamdi’s collaboration.

After completing their growth, the pure lines were included in a half-diallel crossbreeding program, resulting in fifteen hybrids. In the subsequent spring season, the genetic structures obtained from the first season, along with their six parental lines and the standard hybrid (Jenan), were compared under the influence of spraying with three levels of nano-sized potassium.

Key findings of the research indicated that increasing the level of nano-sized potassium to 3 grams per liter improved most of the studied genetic traits, including biochemical, vegetative and floral growth, yield-related traits, and fruit quality. The parent pi-Bee emerged as a promising candidate due to its general and specific adaptability to most studied traits. The study also recommended maintaining the purity of the lines used, utilizing 3×1 and 4×1 hybrids for enhanced production, and applying nano-sized potassium fertilizer at a concentration of 3 grams per liter to tomato plants. Furthermore, the researcher suggested exploring the suitability of other pure lines for Iraqi environmental conditions and investigating the response of new hybrids to different nanonutrients.