scholarly journals Molecular and Genetic Aspects of Grain Number Determination in Rice (Oryza sativa L.)

2021 ◽  
Vol 22 (2) ◽  
pp. 728
Author(s):  
Changxi Yin ◽  
Yanchun Zhu ◽  
Xuefei Li ◽  
Yongjun Lin

Rice grain yield is a complex trait determined by three components: panicle number, grain number per panicle (GNPP) and grain weight. GNPP is the major contributor to grain yield and is crucial for its improvement. GNPP is determined by a series of physiological and biochemical steps, including inflorescence development, formation of rachis branches such as primary rachis branches and secondary rachis branches, and spikelet specialisation (lateral and terminal spikelets). The molecular genetic basis of GNPP determination is complex, and it is regulated by numerous interlinked genes. In this review, panicle development and the determination of GNPP is described briefly, and GNPP-related genes that influence its determination are categorised according to their regulatory mechanisms. We introduce genes related to rachis branch development and their regulation of GNPP, genes related to phase transition (from rachis branch meristem to spikelet meristem) and their regulation of GNPP, and genes related to spikelet specialisation and their regulation of GNPP. In addition, we describe other GNPP-related genes and their regulation of GNPP. Research on GNPP determination suggests that it is possible to cultivate rice varieties with higher grain yield by modifying GNPP-related genes.

Agriculture ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 167 ◽  
Author(s):  
Kifayatullah Kakar ◽  
Tran Dang Xuan ◽  
Saidajan Abdiani ◽  
Imran Khan Wafa ◽  
Zubair Noori ◽  
...  

Rice is an important staple food for Afghans. Its production has been increased, and attention is needed to improve grain quality. Experiments were conducted to evaluate the growth, yield, physicochemical properties, antioxidant activity, and morphological structures of four exotic rice varieties widely grown in Afghanistan (Attai-1, Jalalabad-14, Shishambagh-14, and Zodrass). Antioxidant activities, including 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), of rice grain were determined. A scanning electron microscopic observation was conducted on the cross-cut section of dehulled rice grains. The results showed a wide variation among four rice varieties for growth, grain yield, physicochemical properties, antioxidant activities, and morphology. Tiller and panicle number per hill, 1000-grain weight, grain yield, and antioxidant activities were found to be highest in Jalalabad-14. Attai-1 showed lower amylose, protein, and lipid contents with a high number of perfect grains, consequently enhanced taste point (score of quality). Grain yield, protein, and amylose contents showed a negative correlation with antioxidant activities. Accumulated structures in Attai-1, Shishambagh-14, and Zodrass were normal; however, Jalalabad-14 increased protein bodies and its traces in the amyloplasts. Information on yield potential, grain quality, and nutritional value of these exotic rice varieties may useful for sustainable food provision and nutritional improvement of rice in Afghanistan.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11668
Author(s):  
Ke Wu ◽  
Izhar Ali ◽  
Huimin Xie ◽  
Saif Ullah ◽  
Anas Iqbal ◽  
...  

The current farming system in China is heavily reliant on synthetic fertilizers, which adversely affect soil quality and crop production. Therefore, the aim of this study was to assess the effect of different nitrogen (N) and phosphorous (P) fertilizer application rate on the growth, yield, and yield components of rice cultivars in the Binyang, Beiliu and Liucheng sites of southern China in the early (March to July) and late season (August to December). The study consisted of three fertilization regimes—CK (N0P0); N180P90 (180 kg N + 90 kg P2O5 ha−1) and N90P45 (90 kg N ha−1 + 45 kg P2O5)—conducted at each of three different experimental sites with four cultivars (Baixang 139, Y Liangyou 1, Guiyu 9, and Teyou 582). Results showed that the leaf area index (LAI) was 38.8% found higher in Guiyu 9 compared with Baxiang at reduced fertilization (N90P45). N90P45 resulted higher dry matter production at the heading (9411.2 kg ha−1) and maturity (15319.5 kg ha−1) stages in Teyou 582 at Beiliu. Fertilization (N180P90) had higher effective panicle number (4,158,800 panicle ha−1) and grains panicle−1 (113.84 grains) compared with other treatments. Teyou 582 treated with N90P45 and Y Liangyou 1 treated with N180P90 improved seed setting rate average by 82.91% and 72.17% compared with other treatments at Beiliu in both seasons, respectively. N0P0 and N90P45 increased the thousand-grain weight (TGW) of Y Liangyou 1 at Binyang (27.07 g) and Liucheng (27.84 g) during the early and late seasons, respectively. In Beiliu, the N90P45 treatment (6611.7 kg ha−1) of Teyou 582 increased grain yield compared with other treatments. Overall, our results suggested that reducing N and P at the ratio of 90:45 kg ha−1 in Teyou 582 and Y Liangyou 1 could increase rice grain yield and yield components.


2021 ◽  
Vol 58 (1) ◽  
pp. 43-48
Author(s):  
Dalibha Pathak ◽  
Umesh Ch. Kalita

Sixteen genotypes of rice (including one check) were evaluated on 18 quantitative traits during sali (August), 2018 in a randomized block design with three replications at Instruction cum Research Farm, Department of Plant Breeding and Genetics, Assam Agricultural University, Jorhat to study the nature and magnitude of variability, heritability and genetic advance under delayed sown condition. The analysis of variance for 18 quantitative traits revealed the presence of significant differences for grain yield and its component characters. The highest genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) was observed for chaffs per panicle followed by grains per panicle, spikelet sterility (%), spikelets per panicle, grain yield (kg/ha). A high heritability coupled with high genetic advance was observed for plant height (cm), spikelets per panicle, spikelet sterility (%), chaffs per panicle, grains per panicle, grain yield (g/hill), grain yield (kg/ha), biological yield (kg/ha), straw weight (kg/ha) and harvest index (%) indicating that selection might be effective for improvement of these characters under delayed sown condition with low input. From the findings of this investigation, one genotype viz., Gandhari emerged as the outstanding genotype which yielded 4170 kg/ha and could be directly used for cultivation in delayed sown situation with low inputs. Some other promising genotypes that yielded higher than the check Manoharsali under delayed sown condition were JR 29, JR 16, Basundhara and JR 60 and could be utilized as potential parental material in the hybridization programmes designed to develop suitable rice varieties for delayed sown situation.


2017 ◽  
Vol 47 (3) ◽  
pp. 185-194 ◽  
Author(s):  
Adriano Stephan NASCENTE ◽  
Ruby KROMOCARDI

ABSTRACT The upland rice farmers in Suriname use local varieties and low level technologies in the field. As a result, the upland rice grain yield is low, at about 1 000 kg ha-1. Our objective was to evaluate the use of upland rice cultivars from Suriname and Brazil, and the effect of nitrogen, N, phosphorus, P, and potassium, K, fertilizers on cultivation variables. We undertook four field trials in the Victoria Area, in the Brokopondo District, using a randomized block design each with four replications. The most productive rice varieties were BRS Esmeralda (grain yield 2 903 kg ha-1) and BRS Sertaneja (2 802 kg ha-1). The highest grain yield of 2 620 kg ha-1 was achieved with a top dressing application of 76.41 kg N ha-1 20 days after sowing. For P, the highest grain yield of 3 085 kg ha-1 was achieved with application of 98.06 kg ha-1 P2O5 applied at sowing. An application rate of 31.45 kg ha-1 of K2O at sowing achieved the highest grain yield of 2 952 kg ha-1. Together, these application rates of N, P and K resulted in rice grain yield of about 3 000 kg ha-1, which is three times greater than the national average for upland rice. We demonstrate that the use of improved rice varieties matched to the local conditions, and application of appropriate fertilizers, are management practices that can result in significant increases in rice grain yield in Suriname.


2020 ◽  
Vol 7 (01) ◽  
pp. 22-27
Author(s):  
Nalwida Rozen ◽  
Gusnidar Gusnidar ◽  
Nurhajati Hakim

A series of on-farm fi eld experiments were conducted in two locations in Padang, Koto Panjang and Koto Tingga, West Sumatera, Indonesia in 2015. The purpose of the experiment was to establish the formula of organic fertilizer derived from Tithonia supplied with micro nutrients, Zn and Mn, on rice. The experiments were conducted using completely-randomized block design with six treatments and three replications. The treatments were P = Tithonia Organic Fertilizer Plus (TOFP) + 3.0 kg Mn.ha-1, Q = TOFP + 3.0 kg Mn.ha-1+ 3.0 kg Zn.ha-1, R = TOFP + 4.5 kg Mn.ha-1 + 6 kg Zn.ha-1, S= TOFP + 4.5 kg Mn.ha-1+ 9 kg Zn.ha-1, T = TOFP only, U = 100% chemical fertilizer only. Treatment with micro nutrients as addition to TOFP (TOFP+ 3.0 kg Mn.ha-1 and TOFP+ 3.0 kg Mn.ha-1+3.0 kg Zn.ha-1) increased rice grain yield by 80 g per clump.


1970 ◽  
pp. 14-17
Author(s):  
Mishri L Shah ◽  
Rambaran Yadav

A field experiment was conducted at Regional Agricultural Research Station, Parwanipur in 1998/99 and 1999/00 with an aim to find out the alternate management practices to compensate the loss in the grain yield due to flood. Irrespective of the varieties and transplanting dates, age of seedlings had no effect on grain yield of rice. But transplanting dates had significant effect on grain and grain contributing characters. The yield of rice transplanted at 1 Sept was 25.6 and 37.5% less in 1998/99 and 1999/00 respectively as compared to rice grain yield of 14 July transplanting. Radha 11 registered the highest grain yield of 4086 kg ha-1 in 1999/00 and 2662 kg ha-1 in 1998/99, which was at par to the yield obtained by Sabitri at the same year. The interaction effect of the age of seedlings, transplanting dates and varieties were found significant in both the years. 25 days old seedlings transplanted on 14 July in 1999/00 of rice varieties Masuli and Radha 11, produced statistically the similar yield. Radha 11 was the best among the tested varieties. 25 days old seedlings of Masuli, Basmati, Sabitri and Radha 11 can be recommended to transplant as late as Sept 1 .Key words: Age of seedlings; Rice; Transplanting datesDOI: http://dx.doi.org/10.3126/narj.v4i0.4858Nepal Agriculture Research Journal Vol. 4&5, 2001/2002Page: 14-17Uploaded date: 7 June, 2011


1987 ◽  
Vol 38 (1) ◽  
pp. 49 ◽  
Author(s):  
FR Bidinger ◽  
V Mahalakshmi ◽  
GDP Rao

The finding that the more than 50% of the variation in grain yield of pearl millet breeding lines in two different drought stress treatments could be attributed to variation in yield potential and time of flowering was used to develop a drought-response index (DRI) based on the residual variation in grain yield, adjusted for experimental error. DRI was positively correlated to measured yield in the drought treatments, and independent of both yield potential and time to flowering. DRI in both midseason and terminal stress treatments was unrelated to yield component structure in the irrigated control treatment, indicating that selection for plant type under non-stressed conditions will not influence drought response. DRI was correlated to both grain number per panicle, and grain yield per panicle in both stress treatments, suggesting differential ability to maintain normal grain number, and/or that grain yield per panicle was an important factor in response to stress. Maintenance of panicle number did not seem to be important for maintenance of yield under drought stress. The correlation of DRI and individual panicle yield was of sufficient magnitude for the latter to serve as a selection index in terminal stress. The use of a DRI as a component of breeding for better adaptation to stress is discussed.


2021 ◽  
Author(s):  
PengLin Zhan ◽  
Xin Wei ◽  
Zhili Xiao ◽  
Xiaoling Wang ◽  
Shuaipeng Ma ◽  
...  

Abstract Grain size and grain number play extremely important roles in rice grain yield. Here, we identify GW10 , which encodes a P450 subfamily protein and controlls grain size and grain number by using Lemont ( tropical japonica ) as donor parent and HJX74 ( indica ) as recipient parent. The GW10 locus was mapped into a 20.1 kb region on the long arm of Chromosome 10. Lower expression of the gw10 in panicle is contributed to the shorter and narrower rice grain, and the increased number of grains per panicle. Furthermore, the higher expression levels of some of the brassinosteroid (BR) biosynthesis and response genes are associated with the NIL- GW10 , which strongly suggests that the GW10 is a key node in the brassinosteroid-mediated regulation of rice grain shape and grain number.


2012 ◽  
Vol 37 (3) ◽  
pp. 433-439
Author(s):  
MA Haque

Field experiments were conducted at Patuakhali Science and Technology University research farm during 2009 T. Aman season to investigate the effect of tidal submergence on potassium nutrition and yield of rice. The experiment included two levels of irrigation water source- i) tidal water and ii) ground water, and three levels of fertilizers- i) absolute control (no fertilizer), ii) NP (K omission), and iii) NPK (K addition). The rice varieties were BR23 (HYV) and Lalmota (traditional variety). A general increase in growth, yield and yield contributing parameters were found due to irrigation with tidal water. Tidal water contributed about 19% (BR23) and 11% (Lalmota) higher grain yield in Aman season 2009 compared to that grown with ground water. Potassium contents of rice grain and straw were always higher when plants are irrigated with tidal water. In general, tidal submergence increased K uptake of rice. The K uptake by BR23 under tidal water was about 47, 43 and 8 kg/ha more than those recorded with ground water irrigation under absolute control, K omission and K addition treatments, respectively whereas it was 31, 21, and 68 kg/ha, in Lalmota. The results indicated that whether fertilizers were applied or not plants absorb considerable amount of K from tidal water. Bangladesh J. Agril. Res. 37(3): 433-439, September 2012 DOI: http://dx.doi.org/10.3329/bjar.v37i3.12086


2021 ◽  
Author(s):  
Xiaofang Yang ◽  
Xiaoling Zhao ◽  
Zhengyan Dai ◽  
Feilong Ma ◽  
Xuexia Miao ◽  
...  

Abstract microRNAs (miRNAs) are promising targets for crop improvement of complex agricultural traits. Coordinated activity between/among different miRNAs may fine-tune specific developmental processes in diverse organisms. Grain size is a main factor determining rice (Oryza sativa L.) crop yield, but the network of miRNAs influencing this trait remains uncharacterized. Here we show that sequestering OsmiR396 through target mimicry (MIM396) can substantially increase grain size in several japonica and indica rice subspecies and in plants with excessive tillers and a high panicle density. Thus, OsmiR396 has a major role related to the regulation of rice grain size. The grain shape of Growth Regulating Factor8 (OsGRF8)-overexpressing transgenic plants was most similar to that of MIM396 plants, suggesting OsGRF8 is a major mediator of OsmiR396 in grain size regulation. A miRNA microarray analysis revealed changes to the expression of many miRNAs, including OsmiR408, in the MIM396 plants. Analyses of gene expression patterns and functions indicated OsmiR408 is an embryo-specific miRNA that positively regulates grain size. Silencing OsmiR408 expression (miR408KO) using CRISPR technology resulted in small grains. Moreover, we revealed the direct regulatory effects of OsGRF8 on OsMIR408 expression. A genetic analysis further showed that the large-grain phenotype of MIM396 plants could be complemented by miR408KO. Also, several hormone signaling pathways might be involved in the OsmiR396/GRF-meditated grain size regulation. Our findings suggest that genetic regulatory networks comprising various miRNAs, such as OsmiR396 and OsmiR408, may be crucial for controlling rice grain size. Furthermore, the OsmiR396/GRF module may be important for breeding new high-yielding rice varieties.


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