Effects of Planting Date on the Floret Anatomy and Yield of Rice Varieties in Khuzestan
Journal Title: Iranian Journal of Field Crops Research - Year 2019, Vol 17, Issue 4
Abstract
Introduction 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. Materials and Methods 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. Results and Discussion 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. Conclusions 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.
Authors and Affiliations
A Gilani, S. A Siadat, S Jalali, K Limouchi
The Effect of Epibrassinolide Application on Photosynthetic Material Allocation, Drought Tolerance, and Seed Yield of two Pinto Bean Genotypes (Phaseolus vulgaris L.)
Introduction Common bean (Phaseolus vulgaris L.) is a food crop with high protein, fiber, and minerals. One of the important issues in the formation of seed yield is how photosynthetic materials are allocated in plants....
Improving Yield, Yield Components and the Absorption of Nutrients of Wheat by Growth Stimulants under Normal Irrigation and Drought Stress
IntroductionDrought stress is one of the most important factors in reducing crop production in many arid and semi-arid regions of the world. In recent years, the use of growth stimulants to prevent the excessive use of c...
The Use of "Stress Memory" to Improve Drought Stress Tolerance in Potato
Introduction Potato (Solanum tuberosum L.) as a drought sensitive crop is one of the main sources of human nutrition in different countries and it is cultivated almost all over the world. It is predicted that among the 2...
Study of Changes in Long-term Wheat Production Trend and Factors Affecting it in North Khorasan Province: I- Irrigated Wheat
IntroductionOne of the main challenges of modern agriculture in ensuring food security is development of strategies to deal with potential negative impacts and adapt to climate change. To address this challenge, it is cr...
Yield of Safflower (Carthamus tinctorius L.) Cultivars in Response to Phosphorus Application and Its Efficiency Indices
Introduction: Phosphorus is the third most important nutrient in crop production after nitrogen and potassium. It is involved in all biochemical processes, energetic compounds, and energy transfer mechanisms. Phosphorus...