نشریه نهال و بذر
سال بیست و دوم شماره 3 (تابستان 1385)

In order to study the effects of agronomical factors on grain and oil yield, yield components and oil percent of two canola spring genotypes, an experiment was conducted at Agricultural Research Station of Gonbad during 2002–2004.The experiment was a factorial split plot in a RCBD with four replications. Two genotypes (Option 500 and S-3) and three seed rates (4, 6 and 8 kgha-1) were arranged in a factorial form in main plots and three row spacings (12, 24 and 36 cm) were subplots. The results of combined analysis showed that although the greater duration of growth in the first year of experiment had the greater 1000-seed weight, but it decreased the seed yield and oil of the first year of experiment rather than the second year of experiment because of producing higher plants, more lodging and lower number of pod per plant and number of grain per pod. The number of seed per pod and 1000-seed weight in S-3 genotype were significantly more than those of Option 500 genotype. Increasing of seed rate increased the number of plant per square meter, but it had not any significant effect on grain yield because of more lodging and lower number of pod per plant. In the first year of experiment (with a prone condition for lodging), the better distribution of plants resulted in decreasing of seed yield with increasing of row spacing. Finally Option 500 genotype with 4 kg seed ha-1 and 12cm row spacing had the highest seed yield and oil (3856 and 1791 kgha-1, respectively).

In order to find resistance sources to Fusarium ear rot among early maturity maize lines and hybrids, an experiment was carried out with 20 different geanotypes arranged in RCBD with two replications in Karaj and Sari Agricultural Stations during 2003 and 2004. In this investigations all ears of plants were inoculated by nail punch technique at flowering stage. At physiological maturity, evaluation was condocted using disease severity index (1-6). The results of combined analysis showed significant differences among geanotypes for disease severity. Frequency of genotypes, resistant to Fusarium ear rot was %10. Based on ranking of genotypes, K SC 500, K SC 302 and K SC 400 were moderately resistant hybrids, while KE 76009/1-2-1-2 and KE 77005/1-5-1 were the most resistant and the most susceptible lines, respectively.

Effects of four different planting and transplanting dates on two long-day cultivars of onion were investigated in Agricultural and Natural Resources Research Station of Neishabour during 2002-2003. Cultivars were planted in nursery in 10-day intervals, beginning from 14 February, then transplanted to the field after 60 days,(from 14 April). They were arranged in split blocks in the form of randomized complete block design with 8 treatments and four replications. Bulb length, bulb width, bulb length/width ratio, number and thickness of edible layers, neck thickness of onion, multikindness and bulb yield were measured during growing season, harvest and storage. Results showed that cultivar statistically affected multikindness. Transplanting date affected number of edible layers, multikindness and yield, significantly, so that the first and fourth dates had maximum and minimum yields, respectively. Finally, regard to the reverse relationship of unsuitable storage traits (neck thickness and bulb length) and yield with first transplanting date, it is recommended that 24 April is the best transplanting date for Neishabour area.

The present research was carried out to collect and assess grape cultivars from different aspects such as cold tolerance, fruit quality, cluster marketability, cluster density, berry quality and size, and introduce the best cultivars of Qazvin province. During 2000-2002, superior and healthy genotypes were identified, and 5 plants from each cultivar or genotype were labeled in different orchards. Finally, 19 cultivars with local names of Mesghali, Mollaei, Fakhri, Shahani Qazvin, Yaghouti, Asgari, Shast-e-Arous, Shani Gerd (Shahani Siah), Yazdandaei, Kareroye Sefid, Kareroye Ghermez, Siah Qazvin, Mishpestan, Bidaneh Sefid, Talaei, Shahroodi, Bidaneh Ghermez, Shani Sefid and Rishbaba were identified. During 2001-2002, different characteristics and phonological stages were recorded on the labeled stock plants using grape descriptors. In March 2001, 20 cuttings were prepared from the stock plants, and cultured in nursery for rooting. Then, 9 plants from each genotype were transplanted to the collection gardon at the Takistan Grape Research Station for further evaluations in the second phase of the project. In the first phase, genotypes showed wide variation for the measured characteristics, so that, among them genotypes of early ripening to late ripening, seedless and seeded, low to high yield, very small to large fruit, early to late flowering, low to high sugar content, different vegetative characteristics, weak to power vigor etc. were observed. Cultivars Fakhri, Shast-e-Arous and Mishpestan had very large berries Yaghouti, Asgari, Bidaneh Sefid and Bidaneh Ghermez contained imperfect seed Shast-e-Arous and Shahroodi had very large clusters Kareroye Sefid and Kareroye Ghermez contained female flower with reflex stamens Shahani, Yaghouti, Yazdandaei and Shani Gerd had very early ripening fruit Siah Qazvin had late ripening fruit Shast-e-Arous and Shahroodi had Good storage ability Fakhri, Asgari, Shast-e-Arous, Shani Gerd, Shahroodi and Bidaneh Sefid had high Brix.

This experimental was conducted to investigate the efficiency of polyethylene mulches and suitable sowing method on row, for cucumber in field in Isfahan during 2000 and 2001. Cultivar of cucumber was Super dominos hybrid. Statistical design was split plot on randomized complete block with four replications. Soil cover in three levels (black mulch, transparent mulch and without mulch) were considered as the main plot and sowing method in two levels (single and double rows) as sub plot. Field management and data collection from different treatments were done during growth period. Results showed that transparent polyethylene mulch had a positive effect on early germination of seeds and precocity production. Yield in transparent, black and non mulch treatments were 57.5, 40.2 and 33.6 (tha-1), respectively. Maximum plant vegetative growth and minimum weed were obtained from black polyethylene mulch treatment. Polyethylene mulches had a favorite effect on soil moisture maintenance in bed. Maximum yield was obtained in double row sowing method, but single row sowing increased the marketability of fruits, length and weight of plants.

In this study, chromosome elimination method was used to develop doubled haploid lines of wheat via crosses with maize. The plant materials were F1 seeds including Kavir/Zagros, Roshan (winter backcross)/ Zagros and Rsh2* 10120/Zagros along with three maize genotypes H1=KSC108, H3=KSC301 and H7=SC704 as pollin source. Two methods of haploid production in wheat involving A: conventional technique and B: detached-tiller culture were used and compared. The traits such as seed set percentage, embryo development and haploid seedling development were studied. As a result of this study, 75 lines of doubled haploid wheat were developed. It was also found that the second method (B) was better than the first method (A). In field, traits such as seed number per spike, 1000 grain weight, heading date and plant height were evaluated and finally 15 doubled haploid lines were selected.These lines are now evaluating in Advanced Regional Wheat Yield Trial.

In order to determine the best sowing date and plant density (space between plants) of okra (Abelmoschus esculentus), a field experiment was conducted in two years (2002-2003) at the Iranshahr Agricultural Research Station. A split plot design in randomized complete block with four replications was used. Four sowing dates (4 and 19 February, 6 and 21 March) were considered as the main plots, and three plant densities (30, 50 and 70 cm plant spacing) as the sub plots. The results indicated significant differences among plant densities for number of capsules/ plant, single capsule weight, capsule length and plant height and fruit yield. The treatment of 30 cm plant spacing, with 12.6 tha-1, had the highest fruit yield. The effect of sowing date was also significant, and the highest fruit yield with 12.9 tha-1 obtained from the sowing date of 6 March. Interaction effects of sowing date and density were significant. The treatment of 30 cm plant spacing in 6 March sowing date with 17.5 tha-1 fruit yield had the highest fruit yield, therefore, sowing in 6 march and 30 cm plant spacing are recommended for okra production in Iranshahr.

Iran is one of the most important distribution areas of Chelcheragh lily
(Lilium ledebouri) in the world. In the process of identification, evaluation and finally commercialization of potential germplasms, propagation of a new plant (new crop) is one of the most important factors that should be investigated. To investigate the influence of scale position, different temperatures and media on the regenerated bulblets indices, and also effect of cold treatment on removal of dormancy of bulblets, separate experiments were carried out. Results showed that outer and middle scales at 20 and 25 oC regenerated more bulblets with better properties than inner scales. Regeneration of bulblets were inhibited completely at 30 oC. The highest number of bulblets were regenerated in middle scales and in tree bark+ tea wastes medium that was not significantly different from those regenerated with outer scale and tree bark+tea wastes, peat+perlite, and sand+perlite. Regenerated bulblets were non-green leaf bulblets and dormant. Bulblets needed to 3-5 oC for 6-8 weeks, until 70-84% of them can produce leaf. In this study, it was also cleared that number of regenerated bulblets in cold passed bulbs treatment did not differ from those of non-cold passed bulb treatment.

Crosses of 40 maize inbred lines with five tester lines, KL17/2-5, K74/1, K1264/1, B73 and MO17, and 10 crosses among tester lines were evaluated in two locations (Karaj and Gorgan) in 2004. Specific combining ability of each line was estimated according to line tester analysis. The highest yields of 11.200 and 11.08 tha-1 were produced by crosses of K3615/2, a late synthetic derived line, with MO17 tetster line and KLM7610/1-13, a CIMMYT germplasm originated line with B73 tester line, respectively.Good combining ability revealed in crosses between inbred lines originated from CIMMYT germplasm, firstly with MO17 and then with B73 tester lines,and inbred lines originated from late synthetic variety with both testers. Results of this study indicated that, in addition to Lancaster Sure Crop (LSC) and Ried Yellow Dent (RYD), there might be two more new heterotic groups in Iranian maize germplasm. LSC CIMMYT germplasm and RYD x Late Synthetic, could be promising heterotic patterns.

Introduction of high yielding as well as high quality rice cultivars is one of the most important activities at Rice Research Institute of Iran (RRII). In 1991, 210 rice lines introduced from International Rice Research Institute (IRRI) to Rice Research Institute of Iran were evaluated in observational and statistical experiments in Mazandaran for two years, and seven lines were selected. These lines had better performance in morphological characteristics, early maturity and yield than other lines. Results of additional experiments showed that Fajr cultivar was high yielding and stable in different environments of Mazandaran province. This cultivar had medium maturity with average yield of 6.5t th-1. According to agronomic experiments, the best planting space for this cultivar was 20 20 and 14 30 cm for traditional and machinery transplanting, respectively. Based on soil analysis and crop requirements, 115, 50 and 50 kgha-1 N, P2O5 and K2O are recommended, respectively. Results revealed that this cultivar is similar to Nemat and Dasht cultivrs in response to diseases and pests, but it is much more tolerant to lodging. Plant height and 1000-grain weight are about 108 cm and 24g, respectively. Fajr is one of the most superior improved rice cultivars with a high cooking quality, which has ever been introduced to the farmers of Mazadaran province since RRII establishment. Due to high adaptability of this cultivar, its cultivation could be extended to other provinces like Golestan, Fars and Khuzestan.