جستجوی مقالات مرتبط با کلیدواژه « پتانسیل عملکرد دانه » در نشریات گروه « زراعت »

In crop season 2012-2013 wheat genotype "Frncln/Rolf07" was introduced to Iran within an international nursery received from CIMMYT and was studied in experiment of evaluation of yield and agronomic characteristics of spring wheat genotypes in international nurseries in temperate regions. Then in 2013-2014 crop season, it was selected in a preliminary regional wheat yield trial under normal irrigation with an average yield of 8114 kgha-1 compared to the check cultivars Parsi, Sirvan, Pishtaz and sivand, respectively, with grain yield of 8.035, 8.022, 6.914 and 7.985 kgha-1. This cultivar was further investigated in the advanced regional wheat yield trial of temperate regions of the country during 2014-2015 and with average grain yield of 7093 kgha-1 compared to 6495 and 6423 kgha-1 yield of check cultivars Parsi and Sirvan, respectively, and was selected for adaptation evaluation. The average yield of M-94-15 line in temperate climate adaptation experiment during the 2015-2017 crop season under normal conditions was 7231 kgha-1 verses 6688 kgha-1 of Parsi cultivar and 6574 kgha-1 of Baharan cultivar and in general, total mean grain yield was 3% higher than the average of whole genotypes. Due to the good condition of M-94-15 line reaction to stripe rust (O-30MR) and leaf rust (O-30MSS) diseases, as well as the resistance to grain shattering and good bread making quality, this line was selected for study at the level of farmers' fields. Wheat line M-94-15 based on its favorable agronomic characteristics, suitable earliness and good bread making quality was released in 2019 as Farin for cultivation in temperate agro-climatic regions.

"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.

Barat variety with the pedigree of SLVS×2/PASTOR and selection history of CMSS98Y03489F-040M-0100M-040Y-020M-040SY-28M-0Y-0SY has been selected from 24thSAWSN, an international bread wheat nursery that received from international Research Center for Maize and Wheat Improvement (CIMMYT) and was evaluated in Elite Regional Wheat Yield Trial (ERWYT) in six southernwarm and dry research stations during 2011-13 cropping season. Results confirmed that this new variety has yield stability in studied research stations in southern warm and dry agro-climatic zone. Considering high grain yield, high level of resistance to different physiological races of causul agents of stripe rust and leaf rust in different locations (hot spots), good grain quality as well as good agronomic performance including: earliness, resistance to terminal heat stress and shattering, it was selected and officially released as Barat in 2016. Barat, is a new bread wheat cultivar adapted to irrigated wheat growing areas in the Southern Dry and Warm Agro-climatic Zone in Iran especially in Khozestan, West Fars, Warm areas in Lorestan, Kerman and Kermanshah, provinces.

Mehreghan cultivar with the pedigree of OASIS/SKAUZ//4*BCN/3/2*PASTOR has derived from second international bread wheat nurseries received from CIMMYT (2ed EBWYT, Bread Wheat Yield Trial) that was evaluated in 2008-09 cropping season in Karaj. This cultivar was evaluated for its adaptability in six research sections in the Southern Dry and Warm agro-climatic Zone of Iran in years 2008-2010. Results showed that this cultivar had a goog yield stability in this Agro- climatic zone. Considering high grain yield, high level of resistance to different physiological races of stripe rust, leaf rust and stem rust in different locations (hot spots), good grain quality as well as good agronomic performance including: earliness, resistance to terminal heat stress and shattering, this line was selected and officially released as mehreghan in 2015. Mehreghan, is recommended for planting in irrigated wheat growing areas in the Southern Dry and Warm Agro-climatic Zone in Iran especially in Khozestan, West Fars, Warm areas in Lorestan, Kerman and Kermanshah, provinces.

The Shush variety with CBRD-3/STORK × DICOCCOIDES pedigree has come out from AREO-ICARDA Irrigated Spring Bread Wheat Improvement Project (AIISWIP) for low latitude of west and center of Asia and north of Africa. The cultivar was selected from adaptability tests in hot and dry climates in the south of the countries during two consecutive years (2006-2008) which carried out at six stations located in the hot and dry climates of Iran. The results showed that the Shush in the evaluating stations had stabile grain yield. High grain yield potential, earliness, resistance to terminal heat stress and shattering, high level of resistance to different stripe rust races, good grain quality were there best characteristics of Shush. This cultivar adapted to irrigated wheat growing areas in the Southern Dry and Warm Agro-climatic Zone in Iran especially in Khozestan, West Fars, Warm areas in Lorestan, Kerman and Kermanshah, provinces.

Increased grain yield in modern wheat cultivars has been achieved by increasing grain numbers in spike, which has been associated with a greater contribution of the more distal grains (C, D& E) in the wheat spikelet. However, because distal grains are smaller and lighter than basal grains (A and B) they reduce the average grain weight of modern wheat cultivars. The objectives of this study was to determine the contribution of basal (A& B) and distal (C& D) grains formed in various positions on of spikelet on winter and facultative wheat grain yield in terminal drought stress and normal irrigation conditions. The experimental design for both trials was a randomized complete block with three replications. Five winter and facultative wheat genotypes were studied in normal irrigation and terminal drought stress conditions at two locations (Karaj and Ardabil) in 2003-04 and 2004-05 growing seasons. Cv. Gaspard winter wheat had the highest grain yield (7288 kg/ha) under normal irrigation, while the genotypes grown under terminal drought stress conditions had no significant differences in grain yield. Combined analysis of variance showed that the effect of the position of grains was highly significant (P<0.01) under normal irrigation conditions. Under drought stress conditions, differences due to position of grains was significantly different (P<0.01), the position of grain × location interaction was also highly significant (P<0.01), indicating a considerable variation for this character in different environments. All genotypes had significant differences in the weight of grains in the basal (A& B =38 mg), and distal (C & D = 27-32 mg) grains in the spikelets with lighter grains in the C (32 mg) and D (27 mg) grains in spikelets. However, the weight of grains in the A and B position in the spikelets were heavier. The contribution of the basal grains to grain yield was about 28%, while the contribution of C and D grains were about 22.6% and 19.6% respectively, under terminal drought stress conditions. Breading line as C-80-10, which produced heavier basal (40 mg under stress and 48 mg under normal irrigation) and distal grains (33 and 39 mg under stress and irrigation conditions, respectively) are suitable for both emvironments. More physiology- breeding researches are needed for selection of genotypes with larger and uniform grain size for regions prone to terminal drought stress conditions in winter wheat areas of Iran.

A simple mechanistic crop growth simulation model “WheaPot” was developed for simulating site-specific wheat yield potential. The model simulates critical phonological stages and dry matter production as a function of temperature and solar radiation. Crop aspects of the model including developmental stages, dry matter production and grain yield are modulated in sub-models. The model requires inputs of site mean monthly weather data (minimum and maximum temperatures in ˚C) and photosynthetically active radiation (PAR in MJ m-2), and plant characteristics such as sowing date, required growing degree days (GDD) for vegetative and reproductive phases, radiation use efficiency (RUE in g MJ-1), and harvest index (HI). The model was verified using different experiments, which were carried out in several locations in Khuzestan province in 2003-2004 and 2004-2005 growing seasons. Comparison of simulated and measured values under non-limiting conditions indicated satisfactory performance of the model in predicting anthesis and maturity dates, and a fair prediction of dry matter production and grain yield with root mean square error (RMSE), 3.5 d, 4 d, 0.65 t ha-1 and 1.69 t ha-1, respectively. The model proved as a useful tool for a rough estimation of wheat yield potential at regional level where there is no access to daily weather data.