نشریه یافته های تحقیقاتی در گیاهان زراعی و باغی
سال نهم شماره 1 (بهار و تابستان 1399)

Nafis variety (line L72), suitable for cultivation in the cold and moderately cold regions of Iran, is the result of the selection and purification in segregating generations derived from the cross Orient×Modena. Selection of single plants was carried out during five consecutive years using pedigree method until accessing pure lines and then pure lines were screened in F6 generation. Pure lines along with Okapi as check cultivar were evaluated in the preliminary yield trial in experimental farm of Seed and Plant Improvement Institute in 2009. The result showed that mean seed yield of L72 with 3650 kgha-1 was 30.7% higher than Okapi. The study of adaptability of selected lines in Karaj, Hamedan, Zarghan and Kermanshah during 2012-2013 and 2013-2014 showed that line L72 with seed yield of 4137 kgha-1 had the highest grain yield among studies genotypes where its seed yield was 6.7% higher than Okapi and had a good yield stability based on environmental variance statistic. Results of complementary trials for line L72 in Karaj, Hamedan, Zarghan, Isfahan, Khoy and Kermanshah during 2014-2015 and 2015-2016 indicated that this line with grain yield of 4336 kgha-1 had higher yield compared to other genotypes. Field disease assessments indicated high tolerance of L72 to sclerotinia compared to check cultivar Okapi. Results of on-farm trials in farmers' field of Kermanshah province showed that line L72 had 13.7% higher grain yield compared to Ahmadi as check cultivar. Results of on-farm trials in farmers' field of Isfahan province under normal irrigation and irrigation cutting from pod setting stage showed that line L72 had 1.2 and 9.1% higher seed yield than Okapi as check cultivar, respectively. Therefore, due to desirable characteristics of line L72 such as higher seed yield and yield stability and relative tolerance to sclerotinia stem rot compared to Okapi as check cultivar, this line was released as Nafis and is recommended for cultivation in the cold and moderately cold regions of the country.

Determining the optimum planting pattern plays a critical role to achieve optimal yield in crops such as sesame. In this study effects of different planting patterns including one, two and three-row cultivation on quantitative and qualitative traits of six sesame cultivars including Halil, Dashtestan 2, Darab 1, Oltan, Yellow white and Naz takshakhe were evaluated using a factorial experiment based on a randomized complete block design with three replications in the research farm of Seed and Plant Improvement Institute. The results showed that the effect of planting pattern was significant for all traits measured except seed oil percentage. Also, the effect of cultivar for all traits was significant. The interaction between planting pattern and cultivar was significant (p≤ 0.01) only for branching number. The highest grain yield obtained from one and two-row planting patterns having 1000 and 1092 kgha-1 grain yields, respectively. In contrast, the lowest grain yield (481 kgha-1) was obtained from three-row planting pattern. Moreover, the maximum grain yield (957 kgha-1) and seed oil percentage (53.3 %), as the most important traits of sesame, obtained from Dashtestan 2 and Darab 1 cultivars, respectively. The results suggested that in selecting the best planting patterns, cultivars characteristics and planting density should be taken into account so that plants can efficiently use environmental factors, which reduce competition among plants in order to reach to the maximum economic yield.

Release of new wheat cultivars with good characteristics such as high yield performance and resistance to diseases for specific regions under rainfed condition is an essential task for sustainability of wheat production. Saein was generated by crossing between: Azar2 and 87Zhong291 (with facultative growth type, high yield performance, good thousand kernel weight and resistance to diseases) in 1999-2000 in Maragheh Research Station. Grain yield means of Saein and Azar2 (as check cultivar) during 2006-2013 cropping seasons in Maragheh Research Station were 2601 and 2493 kgha-1 under rainfed condition and 3529 and 3223 kgha-1 with a supplementary irrigation at the sowing time, respectively. Results showed that Saein had also a specific adaptability in Ardabil regions and grain yield means of Saein (new cultivar), Ohadi and Azar2 (as check cultivars) in Ardabil were 1604, 1267 and 1355 kgha-1, respectively. Results of an on-farm study, in the farmer field in Ardabil province, showed that grain yield means of Saein and Azar2 during 2013-2014 cropping season were 2307 and 2275 kgha-1, respectively. The new cultivar is resistant to yellow rust, resistant to moderately resistant to leaf rust and also resistant to common bunt and dwarf bunt as well as resistant to cold damage, lodging and seed shuttering. New cultivar has winter growth type, white grain color, 76 cm plant height and 33 gr 1000 kernel weight. Based on its good characteristics, this line was released as a new wheat cultivar with the commercial name of Saein in 2015 and was recommended for cultivation in rainfed regions in Ardabil province, in the cold dryland areas in the north west of Iran and also in areas with the potential of supplementary irrigation.

Tea is an evergreen shrub. Oldness of the most cultivated tea shrubs as well as release of new tea cultivars and clones in the country has implemented a need for replacement of old tea shrubs with new tea cultivars. The easiest and cheapest method for propagation of tea is through cutting process but cuttings of tea cannot easily produce root. therefore, they need treatment with hormonal growth regulators. In this study, effect of plant growth regulators IBA and NAA alone and in mixture in three levels, 1000, 2000 and 3000 mgl-1 and ZnSO4 in three levels, 2000, 4000 and 6000 mgl-1 on rooting of semi-hardwood cutting of clone 100 was compared with control (no treatment) in two different planting dates (August and October). This study was conducted based on a factorial experiment using a completely randomized design with three replications. Results showed that effects of plant growth regulators on rooting and loss of cuttings was significant compared to control. The best and the most effective plant growth regulator in usual culture medium was combination of IBA+NNA in level of 2000 mgl-1 (1000 mgl-1 each). The best timing for cutting in tea shrubs was in August.

Nowruz cultivar, with pedigree of GOB/Aleli//Canela/3/Arupo*2/Jet/4/Arupo/K8755//Mora, was resulted from a cross in CIMMYT and subsequent selection in the segregating population and was initially introduced to Iranian national barley breeding in 2007-08 as a pure line. Based on its yield potential and other appropriate agronomic traits this line was selected for further evaluation in the warm regions. Results of observation nursery, barley yield trials and on-farm trials in south warm and dry zone of Iran indicated that Nowruz had a good level of lodging resistance, high number of tillers and high grain yield as well as its desirable agronomic characteristics compared to check cultivars Nimrooz and Zahak. In the Elite Barley Yield Trial conducted in Ahvaz, Darab and Zabol research stations in 2010-13 cropping seasons, Nowruz with average grain yield of 5805 kgha-1 had 9% higher yield compared to Nimrooz check cultivar with grain yield of 5350 kgha-1. Nowruz is a two-rowed spring barley with an intermediate spike density, strong and short stem, high number of tillers and genetic deletion of lateral sterile florets in spike. Also, it shows resistant to moderately susceptible reactions to powdery mildew and barley stripe but completely resistant reaction to net blotch. Based on its desirable agronomic characteristics, Nowruz is expected to be spread over farmer's lands in south warm and dry zone of Iran.

Micrografting is a new method for propagation of plant to create healthy gardens. The aim of this study was to investigate the effect of different concentrations of culture medium and growth regulators on micrografting of some of sweet cherry cultivars in vitro using a factorial experiment based on a completely randomized design at the Khorasan Razavi Agricultural Research Center during 2015-2017. Micrografting with meristem scions from seven sweet cherry cultivars as the first factor were grown on rootstock of "Gisela 6" using cleft grafting in four different treatments of culture medium and growth regulators as the second factor. after grafting the micrografted plants were cultured in different treatments and after three weeks were transferred in MS medium with 1 mgl-1 IBA for rooting and then they were transferred to perlite/peat moss (1:1) for adaptation. The results showed significant differences between cultivars for all indices (except grafting time), but there were significant difference for all indices between treatments and interaction effects at the is probability level. MS culture medium containing 1 mgl-1 BA treatment had the highest successful grafting (39%), leaf number (4.7), longitudinal growth (6.2 cm) and grafting time (3.2 Day). Among the sweet cherry cultivars; "Hajyousefi" for successful grafting (35.4 %) and longitudinal growth (5 cm), "Siah-e Mashhad" for grafting time (3.8 Day), and "Dovomras" for leaf number index (3.5) had better results compared to other cultivars. In total, among successful micro grafted plants, percentage of rooting and adaptation were 41% and 25.3%, respectively. Micrografting of sweet cherry cultivar is a good method to accelerate plant propagation in order to recover unhealthy orchards of the sweet cherry trees.

"Khalil" wheat variety with the pedigree of Bow"s"/Vee"s"//1-60-3/3/Cocoraque 75/4/Chamran has derived from national wheat breeding program. The cross of this variety was made in Karaj in 2003-04 cropping season and then from F2 generation in 2005-06 cropping season, its segregating lines were studied through a shuttle breeding program between Iranshahr and Kelardasht research stations. The new variety was evaluated in Elite Regional Wheat Yield Trial (ERWYT) in the southern warm and dry zones' research stations during 2012-14 cropping seasons. The results confirmed that this new variety has yield stability in the studied research stations in southern warm and dry agro-climatic zone. Considering high grain yield, high level of resistance to different physiological races of stripe rust in different locations (hot spots), good grain quality as well as good agronomic performance and resistance to shattering, this line was selected and officially released as Khalil in 2017. Khalil, is adapted to irrigated wheat growing areas in the southern dry and warm agro-climatic zone in Iran, where in most of these regions a high disease pressure especially occurred by yellow rust is a limited factor for wheat production.

In order to evaluate effect of different seed rates on yield potential of newly released Iranian rainfed wheat cultivars under farmers' field, three separate trials based on factorial experiments were conducted using a completely randomized block design with two replications in the cold (Noorabad), moderately cold (Imanabad) and moderate (Koohdasht) regions of Lorestan province in 2016-17. Three commercial wheat cultivars including Azar2, Oahadi and Baran were used in the cold and moderately cold regions (Noorabad and Khorramabad, respectively), where in the moderate region (Koohdasht) three adapted wheat cultivars for this zone including Karim, Koohdasht and Qaboos were used. Seeding rate factor in all three experiments was four seeding rates of 120, 170, 220 and 270 kgha-1. Results showed that Baran cultivar by using up 170 kg seed per hectare in the cold and moderate cold zones of Noorabad and Imanabad, respectively; and Qaboos cultivar using 120 kg seed per hectare in the moderate zone of Koohdasht had the highest yield performance. Result of this study indicated that higher seeding rates will only increase costs of wheat production per hectare and also will result to waste certified seeds.