Authors:Animesh Sarkar, Tofazzal Islam, Gokul Biswas, Shohidul Alam, Mikail Hossain, and Nur Talukder
The objectives of the research were to isolate phosphate solubilizing bacteria (PSB) from the rhizoplane of rice (Oryza sativa L.) cv. BRRIdhan 29 cultivated in acidic soils of Tangail in Bangladesh and evaluate their performances in phosphate solubilization in both in vitro and in vivo conditions. A total of 10 bacterial strains were isolated and purified by repeated streak culture on nutrient agar medium. Upon screening, five isolates (OS01, OS03, OS07, OS08 and OS10) showed varying levels of phosphate solubilizing activity in agar plate and broth assays. Among them, the strain OS07 (B1) and two previously isolated PSB strains B2 and B3 were selected for evaluation for their performances in rice alone or in combination of TSP (triple super phosphate: P1) and rock phosphate (P2). Plant height and the number of tillers per plant were significantly increased by all PSB isolates when used in combination with TSP but PSB alone did not influence much on plant height and the number of tillers except B1. The levels of mineral nutrients content in rice plant tissues were generally increased by the application of the PSB in combination with TSP, while the performances of B1 isolate was superior in all aspects to B2 and B3 isolates.
In Hungary rice (
L.) is cultivated under flooded conditions. Direct seeding into the soil is applied usually. The optimal sowing date is a key factor necessary to the success of this annual crop because of the relatively short growing season. The main objective of this research was to: (1) analyse duration of period from sowing to emergence at different temperature values, (2) determine base temperature of this phenophase and (3) establish a thermal time model for rice emergence. To do this, growth chamber experiments with 5 Hungarian cultivars were conducted to determine the time to median emergence (E
) at constant temperature of 14 to 34 °C in 2 °C steps. The sowing depth was 2 cm, and moisture was not a limiting factor. It was found that the critical thermal zone, which is of highest practical importance, is between 14 and 16 °C. At these values the E
is 23.9 and 13.4 days, respectively, showing a border between unfavourable and acceptable conditions. In the temperature interval between 26 and 34 °C the time needed for emergence was only 3.3 to 4.4 days. Variety differences were also detected. Base temperature was found between 9.8 and 10.9 °C. The thermal time requirements of 4 cultivars varied between 69 and 73 °C day. Data of field experiment with 9 sowing dates and a pot experiment with 3 sowings confirmed that our thermal time model can successfully simulate the emergence of rice.
Authors:M. Yaghoubi Khanghahi, H. Pirdashti, H. Rahimian, G.A. Nematzadeh, and M. Ghajar Sepanlou
The current study was carried out in both pot and field conditions to investigate the effects of three KSB strains of Pantoea agglomerans, Rahnella aquatilis and Pseudomonas orientalis on nitrogen (N), phosphorous (P) and potassium (K) uptake, nutrient use efficiency parameters and nutrients remobilization in rice (Oryza sativa L. cv. Pajohesh). The experiments included 15 treatments of KSB inoculations, commercial K biofertilizer and K chemical fertilizer. The results showed that the inoculums of all three KSB strains increased the K, N and P uptake by grain and straw, especially when applied in combination with ½ K chemical fertilizer (47.5 Kg/ha) as compared to the control treatment. The highest value of available K in the soil obtained from NPK chemical fertilizer equal to 140.1 and 134.6 mg K per kg of soil in the pot and field experiments, respectively, which were significantly higher than KSB inoculations treatments. Bacterial inoculums coupled with ½ K chemical fertilizer also enhanced the nutrient use efficiency (including agronomic efficiency (AE), apparent recovery efficiency (ARE), physiological efficiency (PE), agro-physiological efficiency (APE), internal utilization efficiency (UE), partial factor productivity (PFP), partial nutrient balance (PNB)) and nutrient remobilization. The results indicated that the bioinoculation with these KSB strains isolated from soil paddy could be considered as an effective way to increase potassium, nitrogen and phosphorus uptake by rice plant and enhance their use efficiency and remobilization to grains in the flooding irrigation conditions.
Authors:L. Ma, P. Xiao, J. Cai, X. Li, Z. Ji, Y. Xia, C. Yang, and J. Bao
Uniformity in the height of main stem and tillers is a key factor affecting ideal plant type, a key component in super high-yielding rice breeding. An understanding of the genetic basis of the panicle layer uniformity may thus contribute to breeding varieties with good plant type and high yield. In the present study, a doubled haploid (DH) population, derived from a cross between
rice variety Zhai-Ye-Qing 8 (ZYQ8) and
rice variety Jing-Xi 17 (JX17) was used to analyze quantitative trait loci (QTL) for panicle layer uniformity related traits. Six, four and three QTL were detected for the highest panicle height (HPH), lowest panicle height (LPH) and panicle layer dis-uniformity (PLD), respectively. qHPH-1-1 and qPLD-1 were located at the same interval on chromosome 1. The JX17 allele(s) of these QTL increased HPH and PLD by 2.57 and 1.26 cm, respectively. Similarly, qPLD-7 and qHPH-7 were located at the same interval on chromosome 7, where the ZYQ8 allele(s) increased HPH and PLD by 3.74 and 1.96 cm, respectively. These four QTL were unfavourable for panicle layer uniformity improvement because a decrease of the PLD was accompanied by decrease of the plant height. qPLD-6 and qLPH-6-1 were located at the same interval on chromosome 6, however here the JX17 allele(s) increased LPH, but decreased PLD, suggesting that this QTL was favourable for improvement of panicle layer uniformity. The markers identified in this study are potential for marker assisted breeding for the improvement of the panicle layer uniformity and ideal plant type.
Authors:M. Nedunchezhiyan, K. Laxminarayana, K. Rajasekhara Rao, and B. Satapathy
A field experiment was conducted at the Regional Centre of the Central Tuber Crops Research Institute, Dumduma, Bhubaneswar for three consecutive years (2006–2008) under rainfed conditions on Alfisols to quantify the effects of strip intercropping on crop yields and yield components. A significantly higher yield was obtained from sweet potato (Ipomoea batatas L.) border rows when pigeonpea (Cajanus cajan (L.) Millsp.) was intercropped. Analyses of sweet potato yield components indicated that the number of roots/plant, root length and root diameter were significantly higher in border rows when rice (Oryza sativa L.), finger millet (Eleusine coracana L.) and pigeonpea were used as intercrop compared to monoculture sweet potato. The number of tubers/plant of sweet potato in border rows was significantly lower when maize (Zea mays L.) was intercropped, but the root length and root diameter were found to increase compared to sole sweet potato. The yields of rice, finger millet, maize and pigeonpea in inside rows in strip cropping were a little higher than in monoculture. The yield difference was mainly due to an increase in the number of seeds/panicle or cob. Sweet potato was the dominant crop when grown with rice or finger millet, but it was the subordinate crop when grown along with maize or pigeonpea. Sweet potato yields were consistently higher in strip intercropping than in monoculture when calculated across all the strips on an equal area basis. A strip intercropping system involving sweet potato + pigeonpea resulted in a higher land equivalent ratio (1.31) and net return ( $623.9) compared to the other forms of intercropping and to monocropping.
Authors:Jerko Gunjaca, Zrinka Knezovic, and Marija Pecina
Asenjo C.A. — Bezus R. — Acciaresi H.A. (2003): Genotype-Environment interactions in rice (OryzasativaL.) in temperate region using the Joint Regression Analysis and AMMI methods — Cereal Res Commun 31: 97
Authors:M. Gholipoor, K. Ghasemi-Golezani, F. R. Khooie, and M. Moghaddam
growth, mineral nutrition and proline accumulation in relation to osmotic adjustment in rice (OryzasativaL.) cultivars differing in salt resistance. Plant Growth Reg. , 19, 207-218.
Effects of salt stress on growth, mineral