SEED AND PLANT IMPROVEMENT JOURNAL
Year:2010 | Volume:26-1 | Issue:2|Papers Count:11

The first step in a plant breeding program, is to evaluate genetic variation in the plant germplasm. In order to study the genetic diversity among barley genotypes, 64 genotypes provided by the Seed and Plant Improvement Institue, Karaj, Iran were assessed using 14 SSR markers. The obtained 128 alleles, had 1 to 17 polymorphic alleles in each locus and 81 polymorph alleles were obtained.Average number of alleles in all of locus were 9.14.Average number alleles in plant in all of locus showed 2.0. Calculated PIC coefficient (Polymorphism Information Content) based on the scored bands ranged from 0.49 to 0.89.Some of the markers showed association with one or more morphological characteristics.Results showed that micro satellite markers could reveal high polymorphism and therefore are helpful for fingerprinting, clustering and marker assisted selection.

Sixteen chickpea lines along with Bivanij cultivar (check) were studied for seed yield stability in dry land conditions in a RCBD with four replications at Krmanshah, Lorestan, Ilam, Gachsaran and Gonbad Research Stations during three cropping seasons (2001-04).The results of combined analysis showed that interaction of genotype x year was significant in each location. Bsed on climatic conditions and analysis of homogeneity of error variances, combined analysis was done for three locations (Lorestan, Kermanshah and Ilam) and two locations (Gonbad and Gachsaran) separately. The results showed that the effects of year x location and year x location x genotype were significant at 1% level of probability. A significant difference was also found among the genotypes at 1% level of probability. Genotypes FLIP 93-93 and S96019 with 1193 and 1181 kgha-1 produced the highest seed yield in Kermanshah, Lorestan and Ilam. Genotypes FLIP 93-93 and FLIP 94-123 with 2257 and 2270 kgha-1 produced the highest yield in Gonbad and Gachsaran.The results of different statistical methods used for assessing yield stability showed that genotypes FLIP 93-93 and FLIP 94 - 30 in Kermanshah, Lorestan and Ilam and FLIP 94-30 and FLIP 94-60 in Gonbad and Gachsaran were the most stable genotypes.

Crown rot disease in some imported rootstocks is a common problem in establishment of intensive and semi - intensive orchards. Native dwarfing apple cultivars are precious genetic resources for selection of genotypes resistant to crown rot, because of their adaptability to the pedoclimatic conditions of Iran. In previous investigation vegetative and productive characters of native apple cultivars were evaluated and cultivars Azayesh, Morabbaei Isfahan, Morabbaei Kamalabad, Zinati and Northern Spy were selected as parents. The open pollinated fruits and seeds were cultivated. All the obtained seedlings, composed of five different genetic populations were inoculated wih Phytophthora cactorum isolates in a controlled condition in greenhouse. Table for defining damage severity was prepared according to the characteristic symptoms on leaves and stems.According to the damage table seed lings were classified within the six groups of susceptibility. Cultivar Morabbaei Isfahan with higher percentage of germination, lower height and adequate resistance to crown rot was selected as the best cultivar. Cultivar Zinati, inspite of lower germination percentage, showed good dwarfing characteristic and tolerance to crown rot.

Objective of the present study was to estimate GCA, SCA and gene action in some chickpea genotypes in drought stress condition by diallel cross analysis (6 x 6). The experiment materials were 15 crosses along with 6 parents in RCBD design with three replications. The experiment was conducted at Sara rood Research Station (Kermanshah) during 2007-2008.Genetic analysis was accomplished with second Griffing and Hayman method. Significance of mean square of the genotypes indicated sufficient genetic diversity among the genotypes.The mean square of general and specific combining ability and Baker quotient showed that traits of days to ripening, plant height and 100 seed weight, due to high Baker quotient were under the control of additive genes, whereas low Baker quotient for the traits of days to flowering, number of primary and secondary branches, number of pods in plant, number of seeds in pod, seed yield and plant width indicated that these traits were mostly under the control of non-additive genes. The mean amount of Baker quotient for traits of lost water in leaf (LWL) and biomass showed the importance of both additive effects and non-additive in controlling these traits. The highest level of specific heritability was found for 100 seed weight and the lowest for number of seeds in pod. The estimation of mean of dominance degree and regression Wr on Vr showed that the traits of primary and secondary branches in plant, number of pods in plant, number of seeds in pod, seed yield and plant width were under the control of genes with over dominance effect, whereas days to ripening, LWL, plant height, biomass, and 100 seed weight were under the control of genes with partial dominance. The parent ICCV96079 and the genotype SEL9324469 x ICCV96079 had the highest effects of negative GCA and SCA and were significant for the trait of early ripening respectively.

Wheat thrips, Haplothrips tritici K. (Thy.: Thripidae) is an important pest of cereals.Host plant resistance is a useful method recommended for controlling the pest. An experiment was conducted in a randomized complete block design with fifteen wheat cultivars and advanced line and four replications in two separate parts in Golpaygan area, Isfahan province during 2000-2002. One part of the experiment was sprayed four times with Fenitrothion (mlha-1) and the other part with water simultaneously. Sampling of the pest population in each plot was done through counting the number of adult thripses collected in ten sweep nets at flowering stage, and nymphs on ten ears at milky and ripening stages. At harvesting time, grain yield and TKW were also assessed. Combined analysis show no significant differences among cultivars for adult population and significant differences (p£0.01) for nymph population. Shotor dandan and Roshan cultivars had the lowest and M-78-20 and Barekat had the highest density of nymphs (8.69, 8.73, 20.9 and 19.71 nymph/spike, respectively) and showed significant differences with other cultivars. Barekat cultivar, in spite of its high density of nymph/spike, had the lowest SSI for TKW, percentage of TKW loss and grain yield loss. Pishtaz cultivar having the highest quantity of mentioned factors was the most susceptible cultivar. Differences between sprayed and non-sprayed parts for yield were not significant but for TKW was significant (p£0.01).

In order to evaluate drought tolerance in some bread wheat genotypes in field and laboratory conditions (germination stage), a research was conducted. Field experiments were carried out in randomized complete block design with three replications in two rain fed and irrigated conditions. To evaluate drought tolerance at germination stage, a factorial combinations of twenty genotypes and four drought levels (0, -0.4, -0.8 and -1.2 MPa) as a completely randomized design with three replications were conducted in laboratory. At the field experiment significant differences were found among genotypes for grain yield in rain-fed and irrigated conditions. Results of correlation analysis showed that Stress Tolerance Index (STI), Mean Productivity (MP) and Geometric Mean Productivity (GMP) were the best indices for identifying of high yield genotypes in both conditions. Based on drought resistance indices, genotypes No.18 and 19 were identified as relatively drought tolerant genotypes. In laboratory experiment characters such as germination percentage, germination rate, seed vigor, root length, shoot length and Germination Stress Index (GSI) were evaluated. Results showed that all of these traits decreased when rate of drought stress caused by polyethylene glycol increased. Germination rate was more sensitive to drought than the germination percentage, and shoot length was more sensitive to drought than the root length. Germination vigor was identified as a more sensitive character to drought in compare to the other germination traits. Genotypes No.2 (Cross Alborz), 6 and 13, were identified as tolerant genotypes in germination stage. Correlation between germination traits in laboratory with STI was not significant. Therefore, based on these results germination traits were not instrumental indicators of drought tolerance in early stages of growth period.

Twenty hulless barley genotypes were assessed by 85 RAPD markers having 10 bps.Thirty five markers (41%) had suitable polymorphism using 227 amplified markers. The average number of amplified segments was 6.48. The size of amplified products varied from 400 to 2700 kb. Primer 540 had the highest and primers 498, 559, 577 and MT9 had the lowest amplified segments. Jacard similarity coefficient ranged from 0.3770 to 0.8.The highest similarity was observed between genotypes no.15 and 16 (0.8) and also between no.2 and 3 (0.759). The cluster analysis based on Jacard similarity and complete linkage method classified hulless barley genotypes into three groups. The results of the cluster analysis corresponded with the pedigree of the genotypes and the genotypes with the similar pedigree were grouped mostly in one cluster. This suggests the efficiency of RAPD markers in detecting genetic diversity of hulless barley germplasm. Principal coordinates analysis showed that five coordinates accounted for only 42.58% of variation which indicated the proper distribution of markers in the hulless barley genome because of relatively low percentage determined by the five first coordinates. Diversity of hulless barley genotypes was also evaluated by 25 agronomic characters using the range of every trait as a percent of mean. The results showed the existence of considerable variability among the genotypes for most of characters. Analysis of regression showed that 20, 19, 18, 14, 11 and 10 markers were informative for spike length, number of grains per plant, grain yield per plant, number of effective tillers, heading date and 1000 grain weight, respectively. From 18 informative markers for grain yield eight were similar with the markers informative for the number of grains per plant which suggests that from molecular view point this character could be regarded as the most important component of grain yield per plant in hulless barley.

Nine species of sect. Heliobrychis of sainfoin were collected from natural habitats across Iran. Number and size of chromosomes as well as karyotypic formula of the populations were assessed using root tip meristemes. The basic chromosome number varied between x=7 and x=8 and their chromosomal types was metacentric and sub-metacentric. The highest genoms length was assessed for 0. scrobiculata (24.26f..lm) and the lowest for 0. lunata (14.76f.lm).0. heliocarpa and 0. lunata were classified as the symmetric class of a and the others as B 0. heliocarpa with 16m formula had the most total form percentage (44.856) and the lowest intra chromosal asymmetrical, and 0. oxyptera with 2m+14sm had the lowest TF% (32.552) and the most asymmetrical karyotype. Using principal components analysis, the first three components justified 96% of the total variance. By cutting dendrogram, resulted from cluster analysis (Ward) based on the karyptipic parameters, species were classified into two classes. The highest distance value was obtained between 0. oxyptera and 0. heliocarpa and the lowest between 0. buhseana and 0. atropatana.

A breeding hexaploid wheat line named later M-84-18 was produced from crossing of Kauz "S" (a CIMMYT bred line) with Azadi cultivar in Zarghan Research Station during 1995-96 cropping season. The obtained F 1 generation was evaluated next season and due to its good charcteristic’s advanced as a superior F2 generation with Kauz "S"/Azadi parentage in 1996-07. The segregating populations derived from this F2 were evaluated and exposed to selection during 1997-2002. An extracted breeding line with accession number of 4-81-66 from those selections was evaluated in the preliminary yield trial of Zarghan Station and was picked based on its high yield as well as its resistance to stripe rust in 2002-03. This line was further tested in the preliminary regional yield trial of temperate zone over seven stations (Karaj, Kermanshah, Nieshabour, Zarghan, Isfahan, Broujerd and Varamin) and with recorded yield of 7.880 tha-1 against 7.998, 8.074, 7.534 and 7.812 tha-1 of Shiraz, Pishtaz, Mahdavi and Marvdasht check cultivars, respectively in 2003-04. This line was tested in advanced and replicated trials over same seven stations in 2004-05 and with recorded grain yield of 7.878 tha-1 compared to 7.214 tha-1 of Pishtaz forwarded to adaptation trials. The adaptation and stability of this line was evaluated in a two years experiment tested over those seven stations plus Mashhad and Yazd during 2005-2007 periods and with grain yield of 8.683 tha-1 against 8.337 of Pishtaz and due to its high resistance to stripe rust and stem rust (Ug99 race) considered for on-farm trials which was followed in 2007-08 over five locations of temperate zone showing an average grain yield of 5.786 tha-1 for M-84-18 against 5.212 tha-1 of Pishtaz check cultivar. The considerable superiority of this line could be due to its high resistance to stem rust race Ug99 carrying virulrnce factors for Sr31, Sr24 and Sr36 evaluated in Kenya during 2006-08 periods. Finally, according to high grain yield potential, resistance to stripe and stem (Ug99 race) rusts (recorded reactions 0-30MR and 10RlMR against 0-40MR and IOOS of Pishtaz for yellow and stem rusts, respectively), good grain quality (seed protein content of 12%, SDS sedimentation volume of 54, Farinography score of 64 against 11.4, 47 and 58 for Pishtaz, respectively) and also good agronomic performance including shattering resistance and earliness this line was named Sivand and officially released in 2009 for cultivation in irrigated farms of temperate zone, in Iran.

Azad is a new high-yielding chickpea (Cicer ari e tinum L.) cultivar for rainfed areas, resistant to ascochyta blight, with erect growth habit a nd large s eed size de v eloped at the Dryland Agricultural Research Institute (DARI). The pure line FLIP 93-93 (FLIP85- l22C I FLIP82-150C II FLIP86-77C) along with other lines were received from ICARDA through CIYT-W-MR-96 experiment in 1996. It was evaluated in preliminary, A test and B test trials for seed yield, agronomic performance and diseases in Sara rood, Kohdashat, Ilam, Gachsaran, and Gonbad research stations during 1997-2003. Due to high potential yield and desirable characters, it was selected and forwarded to trials for stability of seed yield carried out at those stations for three cropping seasons (2001-04) under rainfed condition. FLIP93-93 with a mean seed yield of 1181 kgha-1 in Kermanshah, Lorestan, Ilam and 2258kgha-1 in Gonbad and Gachsaran produced significantly higher yield than checks. Result s of statistical analysis on seed yield, u s ing different methods of stability showed that this line was one of the most stable genotypes. FLIP93-93 together with 66 advance lines were evaluated for resistance to different races of Ascochyta rabiei under field condition at Gorgan, Kermanshah and Gachsaran research stations and in greenhouse in Varamin during 2002-2004. The results showed that this line was highly resistants to the disease in field condition and to 5 races in greenhouse. In on - farm experiments in two locations in Kermanshah (Bisoton and Bilevar) during 2001-2002 FLIP93-93 with 1062 and 803kgha-1 produced significantly higher yield than the local check (Bivanij). In three locations of Kermanshah (Kozaran, Bilevar and Doroodferaman) in farmrs field, this line with 1377, 1100 and 1263 kgha-1 produced 52, 43, 96 percent higher yield than Bivanij. Its yield in two farmer fields in Lorestan was also 15% and 23% higher than the yield of the check cultivar Greet, and in Golestan 25% higher than Hashem, an improved chickpea cultivar. FLIP93-93 was officially registered by Agricultural Research, Education and Extension Organization in 2008 as a new chickpea cultivar named Azad, for cultivation in moderate and semi warm climate of Iran.