Tag Archive rice

SABRAO Journal Volume 48 Issue 3 September 2016

This issue under volume 48 and released in September 2016 contains articles on sorghum, beans, rice, sunflower, okra, etc.

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SABRAO Journal Volume 48 Issue 2 June 2016

In this issue, articles are on wheat, cassava, maize, indian mustard, eggplant, rice, rape seed, etc.

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SABRAO Journal Volume 48 Issue 1 March 2016

This first issue for 2016 covers topics on cereals, melon, maize, rice, corn, sugarcane among others.

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SABRAO Journal Volume 47 Issue 4 December 2015

This final issue for 2015 contains articles on tomato, jatropha, rice, maize, linseed, pea, lentil, fenugreek, rice, etc

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SABRAO Journal Volume 47 Issue 3 September 2015

This issue for 2015 has articles on sesame, okra, cotton, rice, barley, bitter gourd, maize and Indian mustard in Sudan, Myanmar, and India.

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SABRAO Journal Volume 47 Issue 1 March

This first issue for 2015 has articles on cabbage, wheat, corn, tomato and coriander.

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Genetic Analysis of Grain Yield of F4 Populations for Developing New Type of Upland Rice

R. HERAWATI*, MASDAR and ALNOPRI
Crop Production Department, Faculty of Agriculture, University of Bengkulu, Indonesia
*Corresponding author’s email: reny.herawati70(at)gmail.com, reny.herawati(at)unib.ac.id
Email addresses of coauthors: masdar.msdr(at)gmail.com, alnopri_bkl(at)yahoo.co.id

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Summary

High production of rice is closely related to high yield component characters namely the number of filled grains per panicle or the density of grains per panicle. These characters are complex and greatly determine yield. These traits are also controlled by many genes whose expression is influenced by environmental conditions. This research aims to study genetic diversity and inheritance patterns of rice yield characteristics in the F4population and to obtain the best genotypes from the selection. The materials in this research were 190 F3 generation seed numbers from the pedigree selection which consisted of 24 field numbers resulting from single crosses between local varieties (Bugis and Sriwijaya) with both IR7858-1 and IR148 (N22) that are tolerant to drought. Our research used an augmented design with four parents as check varieties. The research showed that the grain yield of F4 populations was polygenic and controlled by additive gene actions. The heritability value and coefficient of genetic diversity for grain yield were classified as moderate and high. The intensity of differentials selection by 10 percent based on the grain weight/hill, increased the middle value of other observed characters, like panicle length by 20.9%, the total number of grain by 48.4%, the filled grain number per panicle by 59.7%, and grain weight/hill by 40.9%. However, it decreased percentage of empty grain/panicle by 87.6%. Selection on higher filled grains and dense panicles, regardless of panicle length should be considered for developing the new plant type for upland rice with high yield.


Key words: Grain yield, F4 population, heritability, genetic variability

Key findings: Studying the inheritance systems of characters to form the desired character is an important step in segregating populations. Selection based on high grain yield in the F4 generation is expected to be significant in the development of high yield new type of upland rice.

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Developing Screening Tools for Early-season High- and Low- Temperature Stress Tolerance in Rice

S.H. JUMAA1, E.D. REDOÑA2, T. WALKER3, W. GAO and K.R. REDDY1*

      1Department of Plant and Soil Sciences, Mississippi State University, Mississippi State, MS 39762, USA.
      2Delta Research and Extension Center, Mississippi State University, PO Box 197, Stoneville, MS 38776, USA.
      3Horizon Ag. LLC, 8275 Tournament Drive, Suite 255, Memphis, TN 38125, USA.
      4USDA-UVB Monitoring and Research Program, Natural Resource Ecology Laboratory, and Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, CO 80523, USA
      *Corresponding author’s email: krreddy(at)pss.msstate.edu
      Email addresses of coauthors: shj44(at)msstate.edu, EdRedona(at)drec.msstate.edu, twalker(at)horizonseed.com, Wei.Gao(at)colostate.edu

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Summary

Temperature is one of the key abiotic stress factors that affect various stages of plant growth and development. In the US Midsouth, rice plants get exposed to variable temperatures depending on the planting date. We hypothesize that rice cultivars vary in their response to temperature, and developing a method for low- and high-temperature tolerance screening will help producers and breeders to select cultivars for management and breeding, respectively. Four rice cultivars, CL152, Bowman, Antonio, and Mermentau along with two hybrids XL 753 and CLXL 745 that were the most commonly grown in the US Midsouth were evaluated in this study for temperature tolerance. Five day/night temperature treatments, 20/12 (very low), 25/17 (low), 30/22 (optimum), 35/27 (high), and 40/32 °C (very high) were imposed after the seedling establishment, ten days after planting (DAP). Growth and developmental parameters including root and physiological parameters were recorded from plants harvested at 39 DAP. Rice cultivars and hybrids exhibited significant variability in their response to low and high temperatures. Based on total low- and high-temperature response indices, relative temperature response scores were derived. Total low-temperature response index values ranged from 18.48 to 23.15 whereas total high-temperature responses index values ranged from 42.01 to 48.82. Antonio, CLXL 745, and Mermentau were identified as sensitive to cold and heat, Bowman as sensitive to cold and moderately sensitive to heat, CL152 was moderately sensitive to cold and heat, and XL 753 was highly cold and heat tolerant cultivars/hybrids tested. These results may be useful for breeders to develop new rice cultivars which could withstand low- and high-temperature conditions during seedling stages. Further large-scale studies are needed to evaluate more cultivars or lines both in the controlled environments and field settings to come up with practical recommendations.

Key words: Rice (Oryza sativa L.), temperature, morpho-physiological parameters, root growth and developmental traits, SPAR, Total Drought Response index (TDRI), TLTRI, Total low temperature response index; THTRI, total high temperature response index; SD, standard deviation; r2, coefficient determination; PH, plant height; TN, tillers number; LN, leaves number, LA, leaf area; LW, leaf weight; SW, stem weight; RW, root weight; AGW, above ground weight; TW, total weight; RS, root/shoot; RL, root length; RSA, root surface area; RAD, root average diameter; RV, root volume; RNT, number of tips; RNF, number of forks; RNC, number of crossing; SPAD, chlorophyll content; Fv’/Fm’, fluorescence

Key findings: Temperature affects all shoot, root and physiological parameters. Cultivar differences were observed for low and high-temperature responses during the early-season.

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