mohammadtaher hallajian

The majority of Citrus species and some related genera in this family produce nucellar embryos. Nucellar seedlings are similar to maternal parents. The existence of such embryos next to the embryo from fertilization leads to the polyembryony phenomenon which during that, two or few embryos are developed in one seed simultaneously. The nucellar embryo is a big obstacle in citrus breeding, however, the aim of producing genetic uniformity in stock production is valuable. In this study, for distinguishing between seedlings resulting from fertility and nucellar seedlings, a leaf sample was prepared from maternal plants and seedlings resulted from seeds of 11 citrus cultivars. After DNA extraction from samples, PCR was performed using 8 microsatellite primer pairs. The results indicated that 8 primer pairs were polymorphic for nucellar or zygotic traits of seedlings in 9 cultivars. The number of all alleles in the population was 45, and the range of alleles amplified by the primers was 3-11 with an average of 5.75. 35 alleles were polymorphic for nucellar or zygotic traits. Among polymorphic primers, TAA41 primer and TAA1 and TAA27 primers produced the highest number of alleles (11) and the lowest number of alleles (3) in studied cultivars, respectively. Polymorphic primers of this research especially TAA45 and TAA33 can be used to identify nucellar and zygotic seedlings of all citrus genotypes, cultivars, and hybrids in different breeding programs.

This study was conducted to identify stable and high-yielding rice mutant lines.

Fourteen mutant lines along with four cultivars Hashemi Tarom-Mahali, Khazar and Gilaneh were evaluated in a randomized complete block design with four replications in Rasht, Chaparsar and Fars province during two cropping years 2015-2016. Stability of genotype was assessed using AMMI indices and AMMI and GGE biplots.

The contribution of genotype, environment and genotype by environment interaction were 41.48%, 31.87% and 24.19% of total variation, respectively. The highest grain yield was obtained in G5 and G12 with 5684 and 5470 kg ha-1, respectively. The ssiMMASV, ssiSIPC, ssiDist and ssiEV identified G5, G9 and G12; and ssiASV, ssiZA and ssiWAAS, G3, G5 and G9 as the best lines. AMMI1 biplot indicated lines G12, G5, G3 and G1 as stable and high-yielding lines. Based on AMMI2 biplot, G12, G4, G17, G9 and G5 were the most stable lines near the origin of biplot. Different views of GGE biplot were also detected that G12 and G5 in addition to having a higher grain yield than overall yield mean were as stable lines. The superiority index identified lines G5, G12 and G7 as the most stable lines. Principal component analysis showed that the superiority index of Lin and Binns and all the ssi indices were suitable indices for identifying stable and high-performance genotypes.

G5 and G12 were the most stable and productive lines and can be used for introducing of the cultivar.

Apricot is grown in a wide range of climatic conditions in Iran, however, it is frequently damaged by late spring frost. In this case, identification of new genotypes tolerant to cold stress is indispensably needed. The objective of this study was to evaluate the genetic population and relationships among 27 apricot accessions (Prunus armeniaca) by 30 microsatellite markers and 11 morphological traits. Based on the PIC values, the SSR loci (UDP96001, UDP96003, UDP98412 and UDP98411) were the most informative markers. The morphological traits were categorized into three components which explained 91.23% of total variation. The two-dimensional PCA plot exhibited that the highest degree of fruit quality and quantity belonged to the susceptible cultivar of Shahrood 48 which showed to be the favorable parent for the production of resistant mutants with high value of fruit traits to late spring frost. Moreover, the close relatedness of Shahrood 48 and its mutants according to the molecular analyses (including a Bayesian clustering approach and a Partial repeated bisection) confirmed the results of fruit traits analysis. The findings suggest that the wide diversity present in Iranian apricot genotypes could be used as a genetic resource for conservation and development of new cultivars resistant to late spring frost and for designing further apricot breeding programs. The promising new mutant genotypes tolerant to cold stress will be evaluated based on morphological markers in further breeding studies.