Aromatic Rice Germplasm Research Articles

English

The microsatellite or simple sequence repeat (SSR) markers were used to determine the allelic diversity and relationship among 48 traditional indigenous aromatic rice germplasm grown under Eastern part of India. Out of 30 primers, 12 primers showed DNA amplification and polymorphism among 48 aromatic rice genotypes. A total of 28 bands appeared by using 12 SSR primers in 48 aromatic rice varieties/landraces. The number of alleles per locus ranged from 1 to 5 with an average 2.08. Out of 28 bands, 25 bands were polymorphic and three were monomorphic bands. The results reveal that all the tested primers showed distinct polymorphism among the landraces/varieties indicating the robust nature of SSR markers. Most of the primers showed highest polymorphic information content (PIC). Phenotypic characteristics are significantly correlated with genotypic characters. The cluster analysis indicates that the 48 traditional indigenous aromatic rice genotypes were grouped into two major clusters. Among the two major clusters, one cluster had 11 varieties and the second cluster had 37 varieties on the basis of the group of land races. Based on this study, the larger range of similarity values using SSR markers provides greater confidence for the assessment of genetic relationships among the varieties. The information obtained from the SSR profile helps to identify the variety diagnostic markers in 48 traditional indigenous aromatic rice genotypes. Significant genetic variation at maximum number of loci between varieties indicates rich genetic resources in rice. The intra and inter genetically variation might be useful for breeders to improve the aromatic rice varieties through selective breeding and cross breeding programs and also protect these unique germplasm under Intellectual Property Rights (IPR). Key words: Aromatic Rice, Oryza sativa, DNA profile, diagnostic polymerase chain reaction simple sequence repeat (PCR-SSR) marker, polymorphism, genetic diversity.

Agro-Morphological Characterization and Assessment of Variability in Aromatic Rice Germplasm

The present studies were carried out to characterize seventy-one aromatic rice germplasm from IGKV, Raipur. These germplasm were characterized and grouped on the basis of anthocyanin pigmentation, plant habit, and awning character. On the basis of pigmentation distribution in 10 plant parts, a total of twelve groups were formed with group one having no pigmentation and group twelve with pigmentation in 9 plant parts. On the basis of plant habit and awning character, three groups of each were formed. The genetic parameters for the ten agronomic traits indicated that the selection of genotypes may be done for fertile spikelets per panicle, spikelet density, spikelet sterility percentage, and hundred seed weight. Thus, on the basis of above characters, the genotypes Tulsi Mala, Baanspati, Ganga Balu, Samund Chini, Tulsi Amrit, Dudh Dhan, Kari Gilas, Shankar Jeera, and Jata Shankar may be selected for future study. DOI: http://dx.doi.org/10.3329/bjar.v37i1.11168 Bangladesh J. Agril. Res. 37(1): 1-8, March 2012

Screening of the Dominant Rice Blast Resistance Genes with PCR-based SNP and CAPS Marker in Aromatic Rice Germplasm

The objective of this study was to determine the genetic diversities of major rice blast resistance genes among 84 accessions of aromatic rice germplasm. Eighty four accessions were characterized by a dominant 11 set of PCR-based SNP and CAPS marker, which showed the broad spectrum resistance and closest linkage to seven major rice blast resistance (R) genes, Pia, Pib, Pii, Pi5 (Pi3), Pita (Pita-2), and Pi9 (t). The allele specific PCR markers assay genotype of SCAR and STS markers was applied to estimate the presence or absence of PCR amplicons detected with a pair of PCR markers. One indica accession, Basmati (IT211194), showed the positive amplicons of five major rice blast resistance genes, Pia, Pi5 (Pi3), Pib, Pi-ta (Pi-ta2), and Pik-5 (Pish). Among 48 accessions of the PCR amplicons detected with yca72 marker, only five accessions were identified to Pia gene on chromosome 11. The Pib gene was estimated with the NSb marker and was detected in 65 of 84 accessions. This study showed that nine of 84 accessions contained the Pii gene and owned Pi5 (Pi3) in 42 of 84 accessions by JJ817 and JJ113-T markers, which is coclosest with Pii on chromosome 9. Only six accessions were detected two alleles of the Pita or Pita-2 genes. Three of accessions were identified as the Pi9 (t) gene locus.

Development of a single kernel analysis method for detection of 2-acetyl-1-pyrroline in aromatic rice germplasm

Because of the high demand for aromatic rice cultivars that command a premium, it is important to have efficient methods for determining 2-acetyl-1-pyrroline (2-AP), the aromatic compound found in rice, that can be used in breeding efforts and to detect aromatic/non-aromatic blended rice in the marketplace. Solid-phase microextraction (SPME) in conjunction with GC/MS was used to distinguish non-aromatic rice (Oryzasativa, L.) kernels from aromatic rice kernels. In this method, single kernels along with 10 μl of 0.1 ng μl−1 2,4,6-Trimethylpyridine were placed in sealed vials and heated to 80 °C for 18 min. During the heating stage volatile compounds, which include 2-AP, were adsorbed onto a SPME fiber. Volatiles were desorbed from the fiber and separated using gas chromatography. 2-AP was quantitated by mass spectrometry using the 111, 83 and 68 m/z ions. The method detected 2-AP in milled rice and brown rice; however, its detection in paddy rice was less successful. In a mixture of aromatic and non-aromatic rice, the aromatic rice kernels were differentiated from the non-aromatic rice kernels using the described method. Therefore, this method can be used to identify segregating from non-segregating progeny during early generations in an aromatic rice breeding program when quantities of seed are very limited and can determine if aromatic rice has been adulterated with non-aromatic rice either through inadvertent mixtures, outcrosses or prepared blends.

Screening of Resistance Genes Linked to Brown Planthopper Using STS Marker in Aromatic Rice Germplasm

Brown planthopper (BPH) is a serious insect pest of rice crop throughout rice growing countries, and yield loss due to its infection can be up to 60%. This study aimed to evaluate efficiency of molecular markers for screening BPH resistance accessions among 86 aromatic rice germplasm Eighty-six accessions of aromatic rice germplasm included two accessions of Tongil type (bred in Korea), 28 accessions of japonica type and 56 accessions of indica type. We applied eight STS markers (pBPH9, pBPH19, pBPH20, pBPH21, AJ09-b, RG457L, RG457B, and 7312.T4A) which were linked to four of BPH resistance genes, Bph1, Bph13(t), Bph10, and Bph18(t) respectively. One japonica type accession, 415XIr352, and six indica type accessions possessed one or four positive bands when tested with four STS markers linked to Bph1 gene. One indica type aromatic rice, Basmati9-93, showed the target bands linked to the Bph10 gene. The other accessions did not show same fragments as the respective resistant lines. Bph13(t) is the most widely introduced resistance gene and only one accession showed positive bands implying that this accession might harbor Bph10 and Bph18(t) genes. Three aromatic accessions, Domsiah, Khao Dawk Mali 105 and 415XIr352 showed gene pyramiding of Bph1 and Bph13(t). Two indica aromatic rice, Ds 20 and Basmati 9-93, possessed at least two BPH resistance genes, Bph1, Bph18(t) and Bph13(t), Bph18(t), respectively. These results indicates that aromatic rice germplasm have narrow diversities of BPR resistance genes.

Characterisation of aromatic rice (Oryza sativa L.) germplasm and correlation between their agronomic and quality traits

Eighty-eight aromatic cultivars collected from Maharashtra state were assessed for determinants of kernel quality (kernel size-shape, test weight and aroma) and grain morphology such as awning, lemma and palea characters, pubescence, colour of sterile lemma and apiculus colour. We, report seven cultivars—‘Girga’, ‘Kothmirsal’, ‘Kala bhat’, ‘Chimansal’, ‘Jiri’, ‘Kalsal’ ‘Velchi’ and ‘Kali kumud’ as indigenous to southern India. Of the 69 cultivars characterized for agronomic traits 36 cultivars were exquisite genotypes and possessed one or more superior traits such as early flowering, dwarf stature, higher number of productive tiller per plant; long panicles; higher number of filled grains per panicle and strong aroma. Variability in aromatic cultivars was assessed on the basis of nine traits placed aromatic rice cultivars in five clusters. Number of cultivars in each cluster ranged from 1 to 33. 27 significant correlations were obtained in the physical, agronomic and grain morphology traits. Aroma was found to be negatively associated with days to 50% flowering as well as with filled grains per panicle. However, correlation between panicle length and effective tillers with aroma was not observed. Therefore, to increase the yield, improvement in length of panicle and increasing number of productive tillers in medium or mild scented cultivars would be the best strategy.

Evaluation of Bacterial Blight Resistance Using SNP and STS Marker-assisted Selection in Aromatic Rice Germplasm

A molecular survey was conducted to identify the presence of the bacterial blight resistance genes (Xa1, Xa4, xa5, xa13 and Xa21) in 86 accessions of aromatic rice obtained from germplasm. The results revealed that the resistance gene Xa4 (32.5%), Xa21 (17%), and xa5 (16%) were widely observed in tested rice germplasm. Among tested rice germplasm, 49 accessions showed the presence of more than one of five R genes, and 37 accessions possessed none of the R gene. TALLi and 05-IRRi-M-46 showed the presence of Xa4, xa5, xa13 and Xa21. Rice race <TEX>$415{\times}Ir352$</TEX> exhibited positive amplicon for the Xa1, Xa4, xa5 and Xa21. Hyangmibyeo1hos, Ir841-85-1-1-2 and Jasmine85 showed the positive amplicon for the Xa1, Xa4 and xa5 genes. Yekywin Yinkya Hmwe and Khao Dawk Mali105 showed the presence of Xa1, Xa4 and Xa21 gene. Masino Basmati showed the presence of xa5, xa13, Xa21 genes. Xa1 and Xa21 genes were noticed in Mihayngbyeo, Tarana Deshi, Mayataung and AZUCENA. Hyangmibyeo2ho, Basmati 6311 and Basmati405 possessed only two R genes such as Xa4 and xa5, and xa5 and xa13, respectively. The evaluation results of bacterial blight resistance genes in aromatic rice germplasm will help in breeding of multi disease resistant varieties.

Comparative assessment of SSR diversity in aromatic rice germplasm

The genetic diversity in 370 aromatic rice germplasms introduced from home and abroad, was investigated by using a total of 60 SSR markers. 361 alleles were detected, with the number of alleles (Na) per loci ranging from 2 to 10. The Nei's genetic diversity index (He) among loci varied widely from 0.104 at RM308 to 0.885 at RM2634 with an average value of 0.663. There was an obvious difference in SSR allelic diversity between indica and japonica rice. Indica rice showed more variation than japonica rice both for Na and He. Meanwhile, the genetic diversity of the landraces was higher than that of the improved varieties, and Na of the improved varieties was 86.5% of the landraces. Analysis of molecular variance indicated that 43.08% of the variation was from genetic differences between subspecies. It was also demonstrated that the genetic differentiation among different rice ecological regions ranged from 1.69% to 14.40%. There was significant differentiation between Southern China and Southwestern China, Central China and Southwestern China, respectively. Cluster analysis showed that 370 aromatic rice varieties were mainly classified into indica and japonica, and aromatic rice varieties from the same areas or the neighboring provinces were basically assigned to the same group.

Characterization of Aroma and Agronomic Traits in Afghan Native Rice Cultivars

In this study, we collected native aromatic rice cultivars from north, east and northeast of Afghanistan, and check cultivars from Japan, Thailand and India. We characterized some important agronomic characters such as plant height, panicle number per plant, grain number per panicle, 1,000-grain weight, grain length and grain width to find the desirable characters for breeding programs. Many of them were classified into tall culm rice according to IRRI index, but had thin and slender grain, and strong aroma which are favorable characteristics in Afghanistan and surrounding regions. The aromatic character was characterized by three methods, 1.7% KOH sensory test, gas chromatography-mass spectrometry-selected ion monitoring (GC-MS-SIM), and polymerase chain reaction (PCR) analysis. These three methods gave similar results. Six out of 10 Afghan native rice cultivars were aromatic and four non-aromatic. Among the check cultivars, Basmati 370, Jasmine 85, Izayoi, Oitakoutou and Jakouine were aromatic and Nipponbare non-aromatic. Improvement of aromatic and high yielding rice and reduction of plant height are the important objectives for rice breeding in Afghanistan. The results showed that Pashadi Konar from Afghanistan has the intermediate plant height, heavier 1,000-grain weight (32 g), longer grain (11 mm) and favorable aroma. Therefore, this cultivar may be a good source of aromatic rice germplasm in Afghanistan. To clarify the genetic nature of aroma in rice, we crossed non-aromatic cultivar Nipponbare with aromatic cultivar Jasmine 85, and examined the aromatic character in the F2 generation by 1.7% KOH sensory test and PCR analysis. Non-aromatic and aromatic characters were segregated at a ratio of 3:1, showing that aroma is controlled by a single recessive gene.

Variability of quality indices in aromatic rice germplasm

Variability of quality indices in aromatic rice germplasm

Agro-morphological and quality characterization of Badshah bhog group from aromatic rice germplasm of Chhattisgarh

India sub continent is a home for aromatic rice diversity. Land races and wild species possess immense potential of most valuable genes which can he effectively utilized in the present day breeding programmes to evolve miracle varieties in rice that possess not high yield potential and quality but also resistant to biotic and abiotic stresses. The present studies were carried out to characterize thirty two aromatic rice accessions of Badshah bhog group from IGKV, Raipur, Chhattisgarh germplasm. These germplasm accessions were evaluated for twenty-two morphological, six agronomical and eight quality characters. The specific genotypes B: 1340, B: 2039, B: 2495, B: 2816, B: 16930 B: 2354, B:1639, B:2094 were identified for quality and agronomical characteristics. These may be used in hybridization programme to achieve desired segregants for good grain quality with higher yield. Key Words: Morphological characters. quality characters, characterization in aromatic rice. doi:10.3329/bjar.v33i3.1607 Bangladesh J. Agril. Res. 33(3) : 479-492, September 2008