In this research a total of 49 accessions in oat collection of National Plant Gene Bank of Iran belonging to four species of AVENA barbata, A. wiestii, A. fatua and A. sativa were studied. The experiment was performed in an observatory design in research field of Seed and Plant Improvement Institute located in Karaj, Iran. The agromorphological traits were measured according to IBPGR descriptor. Based on Shannon index, lemma color had the largest variety (1. 42). In principal component analysis, the first seven components comprised 68. 43% of total variation. Two accessions of 439 (A. barbata) and 449 (A. barbata) were the nearest and two accessions of 447 (A. wiestii) and 115059 (A. wiestii) and were the farthest based on genetic distance. The studied accessions were placed in five groups by K means clustering method. Three discriminant functions were developed justifying total variance in data. The first and second discriminant functions maintained the most distinction between two species of A. barbata and A. sativa and between two species of A. fatua and A. wiestii, respectively. Total results indicated presence of suitable diversity in the studied population based on the measured traits which could be exploited in oat breeding in future. In addition, the discriminant functions developed in this research could be used in distinguishing the relating oat species.

Reducing environmental and economic costs of crop protection is a major concern. In this context, a revived interest in studying allelopathic factors has been noted. In this study, leaf tissue extract from Artemisia siebery, A. auchary and A. scoparia were evaluated for their effects on seed germination and seedling growth of AVENA ludoviciana. Dried leaf tissue was extracted by methylene chloride. The experiment was arranged in a completely randomized layout with three replication. The treatments were three species of Artemisia, and nine levels of leaf extracts (0, 6250, 10000, 12500, 20000,40000,80000, 125000 and 162500 ppm). Results showed AVENA seed germination, root and shoot length were reduced by Artemisia species extracts. A. auchary had more effect on AVENA seed germination. A. scoparia not had effect on AVENA seed germination and estimated reduction of AVENA seed germination by 80000 ppm extract was 48 and 44.7 % for A. auchary and A. siebery, respectively. The maximum inhibitory effects on root and shoot length was observed by A. auchary. The estimated rates of A. auchary extract required for a 50%reduction in AVENA root and shoot length were 6640 and 9970 ppm, respectively.

Considering the effect of tillage on seed density and distribution, predicting wild oat germination in various soil depths, as affected by plowing system, is necessary. An experiment was designed to count number of wild oat seeds in soil samples taken from four depts in two occasions: first-pre spring plowing (soil surface, 0-5cm, 5-10 cm, 10-15 cm), and 15-20 cm). and second post spring plowing ( 0-5 cm, 5-10cm, 10-15). The experiment was run as randomized complete blocks design with 4 treatments (soil depths), 4 blocks (farms), and 5 replications (observations). Results indicated that pri-plowing, surface seeds had the lowest germination rate of 35%. Number of seeds reduced of depth 0-5 cm. viable seeds in pre-plowing were 81% which was significantly lower than the post-plowing 96%. It was also shown that number of seeds increased by 28% in post-plowing samples, but germination was low due to dormancy.

This experiment was carried out to evoluate the allopathic effects of barely aqueous extracts on germination and seedling electrical leakage ofLolium multif and AVENA ludoviciana. The experimental arrangement was factorial included 4 level of aqueous extract concentration of barley (0, 4, 8 and 12 %) and 2 weed seed (Lolium SPP and AVENA ludoviciana) with 4 replications. Results showed increasing the concentration of barley extracts, decreased seedling dry weight and shoot length inLolium SPP and AVENA ludoviciana. Increasing the concentration of barley extracts, increased MDA concentration and seedling electrical leakage inLolium SPP and AVENA ludoviciana seedling. In highest aqueous extracts of barley, highest seedling electrical leakage (52%) and lowest seedling dry weight (0/28) obtained fromLolium SPP seedling.

This experiment was carried out to evaluate the allopathic effects of barely aqueous extracts on germination and seedling electrical leakage of Lolium multif and AVENA ludoviciana. The experimental arrangement was factorial based on RCBD included 4 level of aqueous extract concentration of barley (0, 4, 8 and 12 %) and 2 weed seed spects (Lolium SPP and AVENA ludoviciana) with 4 replications. Results showed the increasing the concentration of barley extracts, decreased seedling dry weight and shoot length in Lolium SPP and AVENA ludoviciana. Increasing the concentration of barley extracts, increased MDA concentration and seedling electrical leakage in Lolium SPP and AVENA ludoviciana seedling. In highest aqueous extracts of barley, highest seedling electrical leakage (52%) and lowest seedling dry weight (0/28) obtained from Lolium SPP seedling.

In order to evaluate the efficacy of molecular method to detect the resistance of weeds to herbicides, 69 resistant or susceptible grass weed biotypes to clodinafop propargyl herbicide, including Lolium SPP. (6 biotype), AVENA SPP. (30 biotype), and Phalaris SPP. (33 biotype) were studied, dCAPS method as a simple method to diagnosis Ile1781Leu amino acid substitution in ACCase enzyme was used. The results of greenhouse experiment for AVENA SPP., Phalaris SPP. andLolium SPP. were 90%, 79% and 100% similar to molecular experiment respectively. In general, the similarity of molecular method with current methods was about 85%. Isoleucine (Ile) to leucine (Lue) substitution at position 1781 (Ile /Leu) was the most common amino acid substitution selected with ACCase-inhibiting herbicide. The partial differences (about 15%) between glass-house and molecular methods also can explain by non-target site mechanism (enhancing metabolism) or another amino acid substitution.