SEED AND PLANT IMPROVEMENT JOURNAL
Year:2012 | Volume:28-1 | Issue:3|Papers Count:14

In this research, an almond (Prunus amygdalus B.) cultivar (Sahand) and four interspecific hybrid rootstocks (HS314, HS312, HS302 and GF677) of Prunus genus were subjected to the salinity levels of 1.5, 3, 6 and 9 dS m-1. The mixtures of NaCl, Na2SO4, MgSO4 and CaCl2, at ratios of 12.8, 11.1, 10.2 and 20.7 (w/v) were used respectively to prepare saline solutions. Based on the results obtained, salinity had a significant negative effect on leaf chlorophyll content, leaf area and dry and fresh weight of root and shoot. Although leaf proline concentration was increased by increasing salinity levels, but different responses were observed among the genotypes in this respect. Most of plant responses were significant in high concentrations of salinity (6 and 9 dS m-1) and there were no deleterious effects on the plants growth in 1.5 and 3 dS m-1 salinity. The variation of leaf proline was significant in all levels of salinity but increasing of proline in Sahand cultivar was lower than other genotypes and HS302, indicated the highest amount of proline in higher salt stress. Total chlorophyll and chlorophyll b were decreased significantly by increasing salinity level, but there was no significant change in chlorophyll a. Salinity led to the significant differences among genotypes related to K+, Mg2+, Ca2+, Na+ and Cl- concentrations of leaves and roots. Concentration of Mg2+, Cl- and Na+ and Na+/K+ ratio in leaves of all genotypes were enhanced by salinity stress, whereas it had not significant effect on Ca2+, K+ concentrations and Na+/ Ca2+ ratio. According to measured parameters, HS314 and GF677 were relatively salinity tolerant than others genotypes.

More than one hundred characteristics of 81 local grape cultivars of Fars province, Iran (Zarghan Grapevine Germplasm Collection) were recorded at different growth stages of plants from 2002 to 2011 using IBPGR descriptor. Fifty one cvs. Were white and 26 were color grapes. According to dendrogram of similarity in white grapes, maximum and minimum similarity degrees belonged to “Ghalati Doodej" with “Siah-e-Arsenjan" and “Rajabi Aghighi Zarghan" with “Yaghooti Zarghan", respectively. All cultivars belonged to Vitis vinifera L. All white cultivars were seeded grapes except “Giehei Zarghan" and "Yaghooti Zarghan". Sex of flower in all cultivars was hermaphrodite except “Mohrsiah Mazayjan”, “Eshkenak Mazayjan Bavanat”, “Aiteh Siah Zarghan” and “Paykomi Doodej” in them flowers were female with descending stamens. Based on budbreak date, four cultivars were late budbreak. “Ghalati Doodej” and “Sezdong Ghalat” cultivars were suitable for juice and verjuice making. “Askari Paykomi Zarghan” and “Najafabadi Zarghan” were autumn frost tolerant cvs. Based on fruit characteristics, all white grape cvs. were classified as table grapes, raisin grapes and juices grapes. “Aiteh Siah Zarghan”, “Rotabi Sefeed Zarghan”, “Najafabadi Zarghan”, “Askari Najafabad Abade”, “Metghali Najafabad Abade”, “Bash Bavanat”, “Keshmesh Sabz Bavanat”, “Rotabi Zarghan”, “Ghalati Doodej”, “Siah-e-Samarghandi Doodej”, Koleheie MohammadAbad” and “Tokhmkabki Mazayjan” were high yielding cultivars. Yield of these cultivars can be due to pruning and high yielding of some cvs, may be due to their adaptation to spur pruning method which is used in head training systems performed in the collection garden.

Responses of some potato cultivars to scab disease (Streptomyces scabies) were evaluated in the field conditions of Isfahan and Freydan in 2007 using a randomized complete block design. Response of cultivars was assessed based on seven infection classes of potato tubers according to NIAB descriptor diagram. For disease assessment, perCentage of infected tubers, disease severity and disease index of tubers were determined. The means were compared according to Duncan`s multiple range test. The results showed significant differences among the cultivars for all assessed criteria. In Isfahan cultivars Milova and Sante had the lowest and Maradona and Granula had the highest infection. In Freydan, cultivars Cosima and Sonate had the lowest and Arinda and Diamont had the highest disease index and disease severity. Combined analysis of the data showed also the similar results.

Response of new local walnut cultivars Jamal and Damavand, a superior local genotype Z67 and commercial cultivars Pedro, Serr, Chandler, Franquette and Hartley to bacterial blight disease was evaluated in 2009. Leaf rejection, leaf-to-shoot extension of blight, direct shoot infection and correlation between blight resistance levels and vegetative growth were studied. Mixed suspension of the most pathogenic strains of the pathogen collected from four locations was used as inoculum. One-year-old grafted seedlings were evaluated for leaf susceptibility in greenhouse using leaf spray method. Based on the results, Serr, Damavand, Jamal and Z67 were relatively susceptible and Pedro, Chandler, Franquette and Hartley were relatively resistant. Adjoining leaf spots and early leaf abscission was frequent in Jamal and Serr. Results of vegetative growth measurement indicated that Pedro and Chandler were slow growing while Serr and Hartley, fast growing and a correlation was observed between vegetative growth and blight susceptibility. With respect to blight resistance, cultivation of Chandler, Hartley and Pedro is all areas of Iran and local cultivars in semi-arid areas can be recommended.

Root and foot rot caused by Phytophthora drechsleri is an important disease of cucumber in field and greenhouse. One of the best control methods of the disease is use of resistant cucumber cultivars or grafting cucumber plants on resistant cucurbit rootstocks. In the present study, resistance of fourteen cucurbit and cucumber cultivars at different growth stages was evaluated in greenhouse conditions using a completely randomized design in two replications. Susceptibility of cultivars was assessed by percentage of dead plants. Cultivars showed different responses to the disease and were classified into five very susceptible, susceptible, moderately susceptible, moderately resistant and resistant groups. Cucurbit cultivars Kadu Halvaee and Kadu Khoreshti Toopor va Kootah, and cucumber cultivars Boskoo and Dastgerdi with 100, 100, 99.30 and 92.34 percentage of dead plants, respectively were very susceptible and cucurbit hybrids RS841, RS107 and RS152 and Kadu Tanbal cucurbit cultivar with 23.60, 20.12, 15.03 and 10.18 percentage of dead plants, respectively were resistant.

Vegetable leafminer, Liriomyza sativae Blanchard, is a serious pest of cucumber in the greenhouses of Iran. In the present study seven currently-in-use cucumber cultivars (Afzal, Jannet, Caspian, Khasib, Nasim, Radiant and Storm) were evaluated for resistance to L. sativae. Antibiosis was measured using some life-history indices in the greenhouse conditions (27±2 °C, 60±5% RH and 16:8h L:D) in a completely randomized design. Results showed significant differences among the cultivars in some life-history indices of L. sativae. Janet and Storm cultivars had the longest larval developmental time (6.78 and 6.69 days, respectively) and highest larval mortality (19.29 percent), comparing to the other cultivars. Janet showed the lowest pupal weight (324.7μg). Based on the cluster analysis, cultivars were classified into three different groups (from the highest to the lowest levels of resistance) as group 1 (Afzal, Jannet and Storm), group 2 (Caspian and Khasib) and group 3 (Nasim and Radiant). Thus, the highly resistant cultivars such as Afzal, Jannet and Storm would be useful in integrated management programs of L. sativae.

To study the relative resistance of alfalfa cold region ecotypes to downy mildew disease, an experiment was carried out with four replications in RCBD with 15 treatments including 13 alfalfa cold ecotypes, one moderately susceptible ecotype (Yazdi) and one moderately resistant ecotype (Nikshahri) as controls in three locations Hamedan, Gorgan and Zanjan (field test in natural conditions) and Karaj (greenhouse test), in 2008. The results of field experiment showed that ecotypes Yazdi and Hamedani with 67.4% and 55.3% mean disease severity (DS), respectively were susceptible, Ecotype Nikshahri with 18.4% was resistant and ecotypes Malek Kandi and Ghargholoogh with 26.8% and 26.3% DS, respectively were moderately resistant. The results of greenhouse experiment were similar to those of the field experiment where ecotypes Yazdi and Hamedani were assessed as susceptible and ecotypes Nikshahri, Ramandi and Ghargholoogh were resistant. In the light of these results, the resistant and moderately resistant ecotypes which also performed high yield and favorable agronomic characteristics can be selected for more investigation towards cultivar release.

Seven rice cultivars (Hassani, Deilamani, Sepidroud, Shahpasand, Saleh, Neda, IRFAON215 and their partial diallel progenies were grown in a randomized complete block design with three replications and were evaluated for protein content and five nutrient mineral elements contents including Potassium (K), Phosphorus (P), Ferrum (Fe), Zinc (Zn) and Manganese (Mn). Analysis of variance indicated significant differences among the genotypes for all studied traits. General combining ability (GCA) and specific combining ability (SCA) were also significant for all traits. Non-additive effects were predominant for all traits due to low value of genetic ratio and ratio of GCA effect to SCA effect. The broad-sense heritability estimates were high for protein content and contents of K, Fe, Zn and Mn. The value of protein content and four mineral elements contents of K, P, Fe and Zn were high in landrace cultivars Deilamani, Hassani and Shahpasand. The GCA effects of these parents were also higher than those of other genotypes for all of traits; therefore, these genotypes could be used as parents in breeding programs for improving nutrient quality traits in rice.

Genetic diversity of 210 genotypes of M. sativa from 21 populations and its association with ecological factors were studied at Research Institute of Forests and Rangelands, Iran using total proteins profiles. On the basis of SDS-PAGE, 44 reproducible bands, protein peptides, were used for analysis and genetic diversity. SDS-PAGE of total proteins showed high inter- and intera-population diversity but no clear differentiation on the basis of origin or source. The Pearson correlation coefficient was used to study the relationship between genetic and ecological factors, total and monthly precipitation mean (mm), maximum and minimum temperature (ºC) and altitude (m). Results indicated that there was an opposite correlation between altitude and total number of alleles and number of frequent alleles. Correlation between genetic and geographical distance matrices was not significant (R=0.0281, P=0.10), analyzed with Mantel test, indicating lack of clinal trends in variation of total proteins. As Iran is the centre of diversity of Medicago, high variations for various parameters are expected. It is suggested that the genetic base of cultivated M. sativa should be broadened by involving diverse parents in the breeding program. Expansion of the genetic base for M. sativa breeding might be accomplished by systematic use of germplasm that differs in protein profiles and has better quantitative traits.

Sixty durum wheat genotypes selected from previous evaluation of National Plant Gene Bank of Iran and Cereal Department Collection comprises of local durum wheat and some cultivars from other countries, were studied. The genotypes were evaluated along with nine durum checks for agronomic traits in an augmented design experiment during 2009-2010 cropping season at Seed and Plant Improvement Institute, Karaj, Iran. Each genotype was planted in six rows of 3m long. The checks were repeated four times among the rows, randomly. The recorded traits were adjusted based on the model of the design. Descriptive analysis of data showed presence of a vast genetic variability among the genotypes for the recorded traits. Correlation analysis among the traits revealed positive correlation between grain yield and grain number per spike (r=0.32**), and grain weight per spike(r=0.38**), whereas its correlation with plant height (r=-0.53**) and length of peduncle(r=-0.42**) was negative. By stepwise regression analysis plant height and date to heading remained in the final model. Factor analysis using principal components, identified 3 factors which covered 67% of total variation in the samples. Plant height, and yield components were present in the factors. Cluster analysis using Ward method grouped the genotypes in six clusters. Fifteen genotypes out yielded the mean of all checks, however only four were superior to the highest yielding checks, i.e. genotypes Nos. 3 (Wc-46198, with 9789 kgha-1), 11(Wc-46031, a Japanese variety with 9927 kgha-1), 10 (Wc-46043, a Japanese variety with 10066 kgha-1), and 55 (P.S.No22, with 10273 kgha-1) which were considered as the best and selected for further evaluations.

In this study 25 wheat genotypes including 22 advanced lines along with two durum (Saji and Zardak) and one bread (Sardari) wheat cultivars were grown in 19 diverisified environments in Kermanshsah, Ilam, Maragheh and Shirvan under both rainfed and supplemtary irrigation conditions during four cropping seasons (2006-2010) in Iran. The large magnitude of the GE interaction in combined-ANOVA of grain yield relative to genotypic effect, sugessted the possible existence of sub-environmental groups for the genotypes. The GGE biplot analysis showed that the cold environments were seprated from the warm environments and these two groups gave dissimilar results in ranking of genotypes. The moderate eviormnents were correlated with the both warm and cold environment groups. The genotypes G8, G17, G23 (Saji), G11, G21 and G19 could be recommended as genotypes with high yield and stability performance. The genotypes G21, G16, G8, G23 (Saji) and G17 were highly adapted to warm environments, while the genotypes G25 (Sardari), G24 (Zardak) and G6 were highly adapted to cold environments. The genotypes G20, G22 and G19 can be considered as genotypes with general adaptability.

Considering the rich diversity of grape germplasm of Iran, the severe cold winter occurred in 2007, provided a chance to evaluate responses of selected superior clones of Iranian seedless grape ciltivars to cold in natural and artificial (in freezer) conditions. Four one-year old branches per plant in each clone were selected and numbers of healthy and damaged sprouts were counted. Based on cold injury percentage, clones were classified into five groups, highly tolerant, tolerant semi tolerant, sensitive and highly sensitive. To assess the freezing temperature range, clones were maintained in freezer in temperatures -12, -15, -18 and -21ºC for 24 and 48 hours. Using correlation coefficients (r pearson), bilateral relationship between cold affected traits was assessed. The global results showed that clone no. 18 of Bidaneh Ghermez cultivar was highly tolerant, clones no. 6 of Asgari and no. 14 of Bidaneh Ghermezi were tolerant, clone no. 14 of Bidaneh Sefid was semi tolerant and clone no. 3 of Yaghoti cultivar was sensitive to cold. Although the cold temperature tolerance range for grape cultivars is normally between -15 to -17ºC, in this study some selected superior clones could tolerate up to -21ºC temperature.

Most of walnut production in Iran comes from seed originated trees with low quality and quantity as product. For breeding new cultivar(s), from 1983 selection of Iranian walnut germplasm was started at Seed and Plant Improvement Institute and at the first phase 117 genotypes were collected. Seedlings of these genotypes were planted in Kamalshahr (Karaj), Torogh, Kahriz and Bastam Horticultural Research Stations and evaluations were done for five years. In Karaj, genotype Z63 was selected together with six other promising genotypes. These seven genotypes and eight foreign walnut cultivars were evaluated for 15 years. Results showed that Z63 was the best among the native selected promising genotypes. The tree has medium vigor, spreading habit, low shoot density and early- medium leafing time. Z63 is a protandrous genotype, so for commercial production it needs a pollinizer cultivar. Pistillate flowering period was medium and the pollen shading period was early. Fruit and kernel weight and kernel percent was 11.41 g, 5.8 g and 50.77%, respectively. The minimum planting distance for this genotype is about 7×7m and its yield varied from 500 kg in 5th year to 4 tha-1 at the maturity. Fruit shape is long elliptic with smooth shell texture. It has relatively low susceptibility to winter frosts and chilling requirements of terminal and lateral buds and catkins were estimated 750, 900 and 650 hours. Growth degree hour (GDH) of terminal and lateral buds and catkins were 14636, 15186 and 9071 respectively. Pistillate flower abscission (PFA) of this genotype showed to be very low. Susceptibility to anthracnose (Gnomonia leptostyla) was also very low. The leaves of this genotype was susceptible to bacterial blight (Xanthomonas compestris), but after infection most of leaves abscised that helps to reject the infection. Unriped fruits of this genotype had the highest resistance among the evaluated cultivars and genotypes. Long term evaluation of this genotype together with other native promising and foreign cultivars led to officially introduction of this genotype as the first and a new walnut cultivar in Iran in 2010 and named Jamal by Cultivar Release Committee of Agricultural Research, Education and Extension Organization.

Although self-incompatibility in walnut has not been reported, but the dicogamy limits self-pollination of walnut cultivars. As the density of female flowers produced by the tree is low, if a high fruit set occurs, yield especially in terminal bearing cultivars will not be high. So breeding of a pollinizer cultivar with proper pollen shading period is highly necessary for increasing fruit production. During the accomplishment of walnut breeding program which started at Seed and Plant Improvement Institute, Karaj, Iran in 1983 and led to the introduction of new cultivar Jamal in 2010, seven promising genotypes of Persian walnut were selected in 1995 and evaluated together with eight foreign cultivars in complementary and specific experiments for a long period. Based on the results of these studies a genotype named Z30 that in addition to having good characteristics such as medium to vigourous growth, erected growth habit and low shoot density, it was an early leafing, protogynous and early repening genotype too, seemed to have suitable characterictics of a pollinizer for walnut cultivars and genotypes. Genotype Z30 had high pollen load with medium to long pollen shading period (11-13 days). Fruit and kernel weight and kernel percent were 13.09 g, 6.26 g, and 47%, respectively. The minimum planting density was 7×7 m and fruit production started 5 years after planting. Its yield varied from 500 kg in the 5th year to about 3 tha-1 at the maturity. Z30 genotype has low susceptibility to winter frosts. Chilling requirements of terminal and lateral buds and catkins were estimated 550, 650 and 400 hours, respectively, while the growth degree hour (GDH) for terminal and lateral buds and catkins were 10512, 11503 and 8567, respectively. The observed Pistillate flower abscission (PFA) of this genotype was low. Susceptibility to anthracnose (Gnomonia leptostyla) was very low especially in the semi-arid climates like Karaj. The leaves and shoots of this genotype were susceptible to bacterial blight (Xanthomonas compestris). Unriped fruits of this genotype were moderately susceptible to the disease. This genotype with a long pollen shading period is a good pollinizer and has a good synchrony with several selected protandrous walnut cultivars like Jamal and foreign early flowering cultivars like Serr. Based on these characterictics, genotype Z30 was officially introduced as a new walnut cultivar in Iran in 2010 named Damavand and by Cultivar Release Committee of Agricultural Research, Education and Extension Organization.