Ghaffar Kiani

Genetic Diversity in Tomato Varieties Assessed by ISSR Markers

ABSTRACT There is a need to expand the information on genetic relationships between tomato (Solanum lycopersicum L.) varieties to improve hybridization breeding. The genetic diversity and relationships among 12 tomato varieties were evaluated by intersimple sequence repeat (ISSR) markers. A total of 69 bands were generated with 9 ISSR primers, of which 53 bands were polymorphic (65.2%). The mean polymorphism index content was 0.29. There was a high degree of polymorphism between tomato varieties. Cluster analysis, based on Jaccard similarity coefficients, grouped varieties into four main clusters. The types of data obtained from this study can be used to select appropriate parents in tomato hybridization breeding. The cv. Super chief had the greatest genetic distance from other varieties and is suitable for hybridization to achieve maximum variability for selection in segregating populations.

Inheritance of southern root-knot nematode resistance in air-cured tobacco

The southern root-knot nematode (SRKN; Meloidogyne incognita) is one of the main pathogens for tobacco. The objectives of this study were to determine the genetic parameters and heritability of SRKN resistance in air-cured tobacco. For this purpose three resistant parents (Urmia3, KY9, K17) and two susceptible parents (Ergo, Burley TMV4) were crossed based on half diallel and analyzed by Hayman’s method for reaction to Meloidogyne incognita. Fifteen genotypes (parents and hybrids) were planted in the greenhouse in a completely randomized design with five replications and inoculated with 2500 J2 M. incognita race 2 one week after transplanting. Investigation of gall index (GI), number of egg masses (NEM) and average number of eggs per mass (AEM) showed significant differences among genotypes. Non-additive effects in AEM and additive effects in GI and NEM played an important role. Narrow-sense heritability was estimated as 0.75, 0.56 and 0.28 for GI, NEM and AEM, respectively, which revealed that AEM is not a suitable trait for nematode resistance identification. Regression analysis indicated that KY9 is an appropriate donor parent for SRKN resistance. Resistance to M. incognita race 2 is conditioned by a single partially dominant gene.

Diversity in Squash Varieties Assessed by ISSR Markers

ABSTRACT The identification of Squash (Curcubita pepo L.) varieties is important for cultivation and breeding to enhance the probability of producing improved cultivars. There is a need to expand the information about genetic relationships between squash varieties for improvement of hybridization breeding programs. The genetic diversity and relationships among 10 squash varieties were evaluated by inter simple sequence repeat (ISSR) markers. A total of 73 bands were generated with eight ISSR primers, of which 45 bands were polymorphic (61.6%). The mean polymorphism index content was 0.32. There was a high degree of polymorphism between squash varieties. Cluster analysis based on Jaccard similarity coefficients grouped varieties into three main clusters. The type of data obtained from this study can be used to select suitable parents in hybridization breeding programs in squash.

Application of PCR-Based Markers for Off-Type Detection in Rice CMS Lines = تطبيق تقنية فحص الواسمات الوراثية (PCR) للكشف عن الأصناف التي تحتوي على خاصية عقم السيتوبلازم الذكري (CMS) من خطوط الأرز

The cytoplasmic male sterile (CMS) lines that are used in production of hybrid seeds in three-line system often get contaminated with their maintainer lines. Using such impure CMS lines in rice hybrid seed production lead to un-uniformity and yield loss in hybrid rice. Laborious and time consuming phenotypic evaluations are used for elimination of off-type plants in CMS multiplication farms. The other option for off-type elimination in CMS lines is application of molecular markers. In this study, PCR-based markers were used for distinguishing five male sterile lines from other five maintainer lines. Results showed that cms marker had ability to differentiate male sterile lines Neda A and Nemat A from their maintainers. Also, drrcms marker differentiated male sterile lines Dasht A, Champa A and Amol-3 A from their respective maintainers. Results of the study demonstrate the use of these two markers for off-type detection in CMS seed multiplication process. This is helpful in promotion of hybrid seed production technology in Iran.