جستجوی مقالات مرتبط با کلیدواژه « باروری » در نشریات گروه « زراعت »

Early vigor, stress resistance, uniformity, high yield, and breeder right protection have turned hybrid cultivar development into the most successful breeding strategy in rapeseed (Brassica napus L.). The goals of this research were to develop the first CMS based rapeseed hybrids in Iran and to evaluate their performance and fertility. The effect of different traits on yield increasing of hybrids was also studied. Seven CMS lines were crossed with R2000 (a restorer-line) and the seed yield of hybrids was tested using a randomized complete block design with three replications in 2019-2020 and 2020-2021. Three of hybrids with 4.64, 4.40, and 4.38 tons per hectare, showed considerable yield and were significantly different than Nilufar, Neptune, and Nima (3.44, 3.37, and 3.30 tons per hectare, respectively), as check cultivars. R2000×A8 demonstrated the highest heterosis (34.71%) to high-check cultivar. All hybrids obtained were normal in terms of fertility, having no male-sterile flowers. Based on the results of principal component analysis and cluster analysis, the simultaneous increase in the number of pods per plant and the thousand seed weight, together with crossing the more distant parents will lead to more high yielding hybrids. The promising hybrids with high yield and remarkable fertility could be released as new cultivars after passing adaptability and stability experiments.

Among the wild relatives of wheat, species in the genus Aegilops have a close relationship to wheat. Aegilops geniculata Roth (2n = 4x = 28; MgMgUgUg) is an allotetraploid, tolerant to various biotic and abiotic stresses that can be introgressed into bread wheat via hybridization and backcrossing. Here, we crossed three bread wheat (Triticum aestivum L., 2n = 6x = 42; AABBDD) cultivars ‘Navid’, ‘Omid’ and ‘Zarin’ with two Ae. geniculata accessions ‘386’ and ‘387’. ‘Zarin’ × Ae. geniculata ‘387’ and ‘Navid’ × Ae. geniculata ‘386’ crosses showed the lowest (11.93%) and highest (48.25%) crossability, respectively. Polyploidy was induced by colchicine treatment in some F1 seedlings and their fertility was compared to non-treated plants. Non-treated hybrid plants with the exception of Zarin’ × Ae. geniculata hybrids also produced F2 seeds. Chromosome configurations in metaphase I of meiosis were mostly univalent along with 3 to 4 rod bivalents. Chromosome numbers in the root tip cells of a sample of F2 seeds ranged from 45 to 65. Fluorescence in situ hybridization (FISH) using (GAA)10 and pTa535-1 as probes, could identify parental chromosomes in the resulting amphiploids.

One of the problems faced by Phoenix dactylifera L growers in different parts of the country is the lack of a favorable fruit set for tissue culture seedlings of some cultivars recently. This study is conducted to investigate the effects of pollen of different cultivars on the fruit set of Phoenix dactylifera L tissue culture and offshoot palms of Barhi, Piaroom, and Mazafati cultivars in the garden of Jahrom Agricultural Research Station. During the years 2018 - 2019, in a factorial experiment, three factors have been performed in three replications with a randomized complete block design. The first factor involves different pollen with five levels (i.e., codes 7001 (control), 7005, 7013, 7030, and Boyer 11 obtained from tissue culture (B11)) with the second factor being the cultivar type in three levels (Barhi, Pyaram, and Mazafati), and  the third one, the type of seedlings, all applied on 90 ten-year-old trees in two levels (tissue culture and offshoot). Results show that the highest percentage of natural fruit set has been observed in Mazafati cultivar with 7013 and 7030 pollens and 7013 pollen in Barhi cultivar. The lowest percentage of natural fruit set belongs to tissue culture method in Barhi cultivar with pollen 7001 (control). In general, 7013 and 7030 pollens have been identified as the most suitable pollinator base to increase the percentage of normal fruit set and reduce parthenocarpic and fallen fruits of Barhi, Piaroom, and Mazafati cultivars obtained from tissue culture and offshoot.

Effective fertility restorer line is one of the essential components of hybrid seed production in rapeseed. The aim of this study was to evaluate the fertility restoring ability in a number of genotypes of rapeseed via test cross. Plant material carrying the fertility restorer gene (Rf) consisted of four lines (two Polima and two Ogura), seven rapeseed hybrids, 14 candidate promising fertile lines and 40 fertile plants selected from F2 populations of two rapeseed hybrids. Cytoplasmic male sterile (CMS) plant material consisted of three lines (two Polima and one Ogura) and sterile plants observed in F2 generation of a hybrid with Polima system. Crosses between fertile and male sterile genotypes were made. The progenies were planted in the field and number of fertile and sterile plants, pod density, shape andlength and number of seeds per pod were evaluated. Number of fertile to infertile plants ratio confirmed monogenic inheritance of fertility restoration and a strong relation between the male sterility system and Rf gene in parent. Genotypes carrying Rf gene had larger anthers, longer filament and bigger petals than sterile plants flowers. Based on homozygosity of fertility gene and the traits studied, promising genotypes of R'1.1, R'4.2 and R'2.1 were selected as effective restorer lines in Polima system.

Rice is one of the oldest cultivated crops. Anatomical changes in plants under environmental stress can reduce the vascular bundles area such as Xylem area; as a result, these changes can protect cells from death and dieback. There was a difference in terms of pollen germination at times after anthers’ opening. Variety Minyhui 63 had the highest germination rate (85%) at time 0 or immediately after anthers’ opening; but for variety Rufipogon with lower germination rate (60%), 50% of pollens were alive after 12 min (longer). The lowest germination rate (34%) was observed in hybrid varieties with an average longevity that even after 40 min more than 50% were alive. Simultaneously between opening of florets, anthers causes high self-pollination in rice, but flowering time under stress can postpone the turgidity and growth of pollens. Matsui and Hisashi (2003) reported that positive correlation between the number of pollen on stigma and morphological characteristics.

The current research was done for recognizing the impacts of different planting dates on morphological traits in five cultivars of rice in Khouzetan. An experiment was carried out by 2 factors as split-plot using randomized complete blocks design with three replications in agricultural research station. 3 planting dates (2.15, 3.5, and 3.25) in the main plots and 5 sorts of rice including Hoveize and hamer (heat tolerance), red Anbori and Champa (sensitive), and Daniel (semi-tolerance) were arranged in the sub-plot.

The result of combined analysis showed the reaction of cultivars were completely related to planting dates and significant difference were observed for interaction effects in %1 and %5 probability level. The highest anther length, stigma length and style length were related to planting dates 1, and 3. Meanwhile, the planting dates with longer anther and stigma had more pollen number. But among cultivars the reaction was completely different, and cultivars with longer anther had shorter stigma. Also cultivars with increasing of pollen and anther surface and pollen number and development of pollen nutrition respectively can prevent of pollen abortion and yield reduction. The highest grain yield was related to the suitable planting date (3.5) that had %62.5 and %18/1. Production increase with respect to. 2.15 and 3.25. Because the second planting date had the suitable stigma, style, anther length and so anther width and more pollen number on the stigma that can increase pollen germination and production. Among the sorts, Hoveize was superior than others and it had higher yield with 50.9% and 36.3% respectively than 2 sorts that are sensitive to heat: red Anbory and Champa. The shorter growth duration (10-13 days) with respect to other cultivars and escape of high temperature was adaptation mechanisms of Hoveize. On the other hand cultivars had different reaction in related to temperature condition.

Therefore, we hope to increase production under stress condition whereas breeding objectives concentrate on the lowering vascular bundles and control length of florets components to increase contacts between pollen and florets and finally, fertility.

In this research, effect of feeding of five pollen sources, apple, pear, almond, apricot and walnut, as 5 treatments on the period of egg to adult, longevity and fecundity of the predatory mite, Typhlodromus bagdasarjani, was studied in a complete randomized design (CRD). Mites kept individually on black mulberry leaf discs at 24±2 °C temperature, 60±5 % relative humidity and a photoperiod of 16:8 (L:D) hours, with a sufficient quantity of the pollens. Results showed that T. bagdasarjani could develop and reproduce when the predatory mite feed on the all of diets. Thus, the pollens can be alternative foods for the mite. The mean of developmental time from egg to adult emergence varied between the treatments from 11.69 to 21.49 days for females and 11.70 to 20.07 days for males. The minimum mean of developmental time of females and males was on walnut, almond and apple pollens and the maximum mean of it was on pear pollen. The mean of longevity varied among the treatments from 17.45 to 31.26 days for the females and 18.23 to 31.44 days for the male insects. The maximum mean longevity was on apricot and almond pollens for females and it had maximum amount on apricot and walnut for males. The minimum mean of longevity of females and males was on pear pollen. Also the maximum means of daily and total fecundity (0.73 and 9.60 eggs/female) were on apple and walnut pollens. The minimum amount of these means was on pear pollen. According to these results, almond and walnut pollens were the most suitable diet for T. bagdasarjani as compared to the other pollens. Among diets, pear pollen had least desirability and nutritional value for the mite.