Seed and Plant
Year:2005 | Volume:20 | Issue:4|Papers Count:11

To analyze the genotype x environment interaction and determine the yield stability and adaptability of barley genotypes, 19 genotypes of barley including 13 Iranian and 6 international genotypes were evaluated in ten different locations during1998-2001 cropping seasons, using AMMI model. Results showed that the main additive effects of genotype and environment and multiplicative interaction effect of genotype x environment were significant that indicated specific adaptability of the genotypes with special environments. In order to identify stable and adaptable genotypes, AMMI model was used. Stability parameters used in AMMI model consisted of SIPC1, EV1 and AMGE1. In addition biplot technique was used to identify appropriate genotypes to special locations. Results showed that genotypes Kozir, Dundy and Schulyer/L.640 with the lowest interaction, and genotypes K-201/3-2, Walfajre/Wl-2291 and 73-M4-30 with the highest interaction were the most stable and unstable genotypes, respectively. Furthermore, genotypes Arass/Cyclon, L.131//Cg/CM and Cl-10143/Walfajre were more suitable for Karaj, genotype Vavilon for Miandoab and genotypes Kavir/Badia"s" and K-201l3-2 for Mashhad.

In order to assess the effects of row and plant spacing on grain and oil yield of safflower, an experiment was conducted in Maragheh for three years (2000-2003) using a randomized complete block desing in factorial arrangement with 3 replications. The factors consisted of two row distances (30 and 50cm), and four plant distances on rows (5, 10, 15 and 20 cm), respectively. Combined analysis results showed that year effect was significant on capitulum/plant, seeds/ capitulum and 1000S.W. Row distance effect was significant on capitulum /plant. Plant distance on row effect was significant on plant height, height of primary branch and capitulum/plant. Oil content and grain yield were affected by row and plant distance interaction. The highest grain yield (1219kgha-1) and oil yield (346 kgha-1)obtained from 30 x 10 cm treatment.

To study genetic of some characters in bread wheat lines under dryland conditions, a diallel crossing design was conducted. Six lines were crossed unilaterally in spring of 2001. In the following year, parents and F1s were evaluated in RCB design with three replications in the Agricultural Research Field of Lorestan University. Plant height, heading date, leaf angle, leaf rolling, chlorophyll fluorescence, flag leaf length, awn length, plant biomass weight, number of seed per spike and spike harvest index were measured. Analysis of variance showed significant differences for all characters except for number of seed per spike and spike harvest index. Data were analyzed by Griffing (method II and model II) and Hayman's methods (Morley and lones method). General combining ability (GCA) was significant for all characters except for chlorophyll fluorescence. Specific combining ability (SCA) was also significant for all characters except for plant height, awn length and plant biomass weight. In general, genes additive effects revealed the effectiveness of selection for plant height. Additive and non additive effects together were effective for selection in segregating population for heading date, leaf rolling, flag leaf length and awn length. Finally non-additive effects were effective for chlorophyll fluorescence and leaf angle.

Four field experiments were conducted to determin relationship between crown cell membrane stability (CCMS) and seed yield quantity and quality of winter rapeseed cultivars. Experiments were carried out in Zanjan, Hamedan, Shahrekord and Karaj simultaneous1y, in years 1998 and 1999. The treatments consisted of 24 winter rapeseed cultivars and four cold stations. A randomized complete block design with three replications was used. The influences of different low temperatures at the primary stages of rape seed life from germination to resetting stage (4-5 leaf stage) were studied by determination of crown cell membrane stability .The results showed that the cold tolerance of rosettes of some cultivars correlated significantly with oil contents of seeds, but not with seed yield. It was cleared that cultivars producing the highest seed yield had not necessarily the best crown cell membrane stability at rosette stage.

Drought stress is one of the factors which damage corn production in many countries and also in Iran, therefore, breeding for tolerance to drought stress has become a major focus in Iran maize program. In the present investigation, combining ability, gene action and genetic analysis of five characteristics including ear diameter, grain yield, ASI, ear length and 1000kw weight were studied in six pure lines of maize and their fifteen hybrids (twenty-one genotypes). The materials were evaluated in two different experiments using a RCBD with three replications in two environments (water stress and normal irrigation) in Safiabad Agricultural Research Center. Data were analyzed with method two and mix-model B of Griffing. Hayman method was used only for graphical and genetical analysis of ear length. Significant differences were observed among enotypes for different traits in both conditions. Based on the results, the dominance variance was responsible for controlling ear diameter, grain yield, anthesis- Silky interval, ear length and 1000kw weight in both conditions, therefore breeding procedures based on inbred lines generation and then cross between them to find the best materials would be important. Generally, in non-stress condition the additive and dominance variances were involved together, but in stress condition the dominance variance was more important than additive variance.

To determine the effect of plant density on yield of a forage sorghum cultivar (Speedfeed) and two promising lines (MFS2 and KFSI), two separate experiments were conducted in 2001 and 2002 at Birjand Agricultural Research Station. A factorial experiment based on randomized completely block design with four replications was used. Different levels of plant density including (20,25,30,35 and 40 plants m-2)were used, and characteristics such as plant height, total leaf number, diameter of stem, stem percentage, number of tillers number of nodes, length of internode, dry forage yield in the first and second harvest and total dry forage yield were recorded. The results from combined analysis of data of two years showed that cultivars were significantly different in all traits except leaf number. The highest internode length and plant height were observed in Speedfeed, the highest nod number, stem percentage and stem diameter in KFS1, and the highest tiller number in MFS2. KFS1 line had the highest dry forage yield in the first and second harvests with yield of 14.7 ton ha-1 and 7.8 ton ha-1, respectively, and 22.52 ton ha-1 total dry forage yield. Different plant densities were significantly different at 1% probability level for stem percentage and stem diameter. Stem percentage and in some cases, stem diameter decreased with increase of density. Interaction between density and cultivar was significant for dry forage yield in the second harvest and total dry forage yield at %5 level. As Speedfeed had the highest wet forage yield in density of 40 plantsm-2 with yield of 8.5 ton ha-1, and KFSl had the highest dry forage yield in density of20 plants m-2with yield of 10.39 ton ha-1 in 2nd hervest. In density of20 plants m-2, SKFl, and in density of 40 plants m-2speedfeed had the highest total dry forage yield with means of 26.2 and 22.3 ton ha-1, respectively. According to the results, the density of 20 plants m-2is recommended for KFS1 and density of 40 plants m-2for Speedfeed.

In order to study the effect of water stress on yield and yield components of bread wheat and determine the critical developmental stages under stress conditions, a field experiment was conducted in Torogh Agricultural Research Station (Mashhad, Iran) in 2000/01 and 2001/02 cropping seasons, using a split plot design based on a randomized complete block design with 3 replications. Main plots were assigned to 7 levels of water stress treatments D1, full irrigation; D2, cessation of watering from one leaf stage to floral initiation, and in other treatments, cessation of watering under rain shelter D3, one leaf stage to floral initiation; D4, floral initiation stage to early stem elongation; D5, early stem elongation stage to emegence of flag leaf; D6, emegence of flage leaf stage to anthesis; D7, anthesis stage to late grain filling (soft dough). Sub-plots were assigned to four bread wheat cultivars: Roshan, Ghods, Marvdasht and Chamran. Results of combined analysis of variance showed, biological yield, grain yield, yield components, harvest index and other traits were significantly affected by water stress treatments. Under D5, D6 and D7 treatments, grain yield decreased compared to D1 by 36.7, 22.8 and 45.6%, respectively. There were also significant differences between genotypes for yield and yield components. Significant correlation coefficients were found between grain yield and number of spike per m2,number of grains per spike, harvest index, spike weight at anthesis and seed set percentage. Under water stress conditions, grain yield was more affected by number of grain per unit area. Results showed, susceptibility of developmental stages of bread wheat to water stress were different. Exposing to water stress in each developmental stages, lead to decrease in yield. Grain filling (D7) and stem elongation (D5) stages were the most critical stages under water stress conditions. The effect of water stress in early pre-anthesis (D6) and tillering (D3) stages was also considerable.

To study the effects of harvesting time and drying temperature and duration on seed viability, vigour and some other characteristics of two oilseed rape cultivar PF7045/91 (Sarigol) and SLM064, an experiment was conducted for two years (2000 and 2001) in Seed and Plant Improvement Institute. Seeds of both cultivars with 45%, 30% and 15% moisture contents were harvested 222, 229 and 236 days after planting and dried in air force oven at 45,55 and 65 centigrade degrees for 12, 18 and 24 hours. Some important characteristics such as primary and final germination percentages, normal and abnormal seedlings number, mean daily germination rate, seedling and primary roots length, fresh and dry seedlings weight and seedling vigour index were measured. Combined analysis of the data showed that the primary and final germination percentages, mean daily germination rate and seedling weight were affected by cultivar x seed moisture contents x year interaction. The highest pecentages of primary and final germination belonged to seeds of cultivar PF7045/91 harvested 222 days after planting with 45% moisture content, and cultivar SLM046 harvested 236 days after planting with 15%moisture content, respectively. Seeds of SLM046 cv. with 15% moisture content produced the highest number of normal seedlings and had higher mean daily germination rate. Seeds of PF7045/91 produced seedlings with higher length and dried and fresh weights compared to SLM046. Seeds of PF7045/91 harvested 236 days after planting with 15%moisture content and dried at 45oC for 12 hours had higher viability. Increase in drying temperature and duration, increased seed viability in PF7045/91. In the light of the results, seeds of SLM046 cv. harvested with 15%moisture content 236 days after planting, dried at 55oC for 24h and seeds of PF7045/91 cv. harvested with 30% moisture content 229 days after planting, dried at 45oC for 18h had the highest quality.

In recent years most activities of Rice Research Institute, has been focused on introduction of high yielding as well as high quality rice cultivars. In 1994, 185 lines introduced from International Rice Research Institute (IRRI) to Rice Research Institute of Iran (RRII), were evaluated in observational and statistical experiments in RRII for two years, and eight lines were selected. These lines had better performance, morphological characteristics, early maturity and higher yield than other lines. Results of different experiments carried out during next five years, showed that line IR67015- 94-2-3, introduced later as Shafagh cultivar was more high yielding and stable in different environments of Mazandaran province compared to the other lines. This cultivar is medium in maturity with average yield of 7.7 tha-1. The best planting space for Shafagh cultivar is 20 x20 and 18 x 30 cm for traditional and machine transplanting, respectively. Based on different experiments on soil analysis and crop requirements, 115 kg N ha-1, 50 kg P2O5ha-1 and 50 kg K2O ha-1 are recommended. Results revealed that this cultivar has similar responses as Nemat and Dasht cvs to all major diseases and pests, but more tolerant to lodging. Its plant height and thousand-grain weight are around 110 cm and 25g, respectively. (Also see Tables 1 and 2 in Farsi Text).

Hirmand is a bread wheat cultivar derived from progenies of a cross made between Bayat cultivar and (JarxCfn -Cno/Saric 70) Jup"s" line. It is of spring habit and early maturity, 90-100 cm plant height, brown spikes and thousand kernel weight of 37gram. It is tolerant to lodging, shattering and diseases. Hirmand has hard grains of amber colour and good yield stability. All selections and evaluations was made in Zahak Agricultural Research Station in zabol. It was also studied in regional uniform yield trials in warm and dry zones Station for adaptation and yield stability (See Tables 1,2 and 3 in Farsi text).

Hamoon is a new bread wheat cultivar derived from progenies of a cross made between Falat and Roshan. It is of spring habit and early maturity, 90-100 cm plant height, white spikes and thousand kernel weight of 40-45 gram. It is tolerant to lodging and environmental stresses(drought and salinity) as will as yellow rust. Hamoon has hard grains of amber colour with averae protein content of 10.5%. All selection and early evaluations, were made in Zahak Agricultural Research Station, Zabol. It was also studied in regional uniform yield trials in warm and dry zone's station for adaptation and yield stability (See Tables 1 to 4 in Farsi text).