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The present study aimed to determine the effect of different organic and inorganic source of fertilizers on growth and performance of rice. The experiment was conducted at two locations: Tinh Bien and Tri Ton AnGiang province with two varieties of landrace rice with AG3 and AG4. Each experiment has seven treatment. Treatments included a combination of organic and inorganic nutrients at sevenrates (F1:80-40-40+ organic manures 10 t ha-1;F2:60-40-40+ organic manures 10 t ha-1;F3: 40+40+40+ organic manures 10 t ha-1;F4: 20-40-40+ organic manures 10 t ha-1. F5:only organic manures 12 t ha-1; F6: control no dose of NPK;F7: farmers used: 120-40-60+ organic manures 12 t ha-1). The experiment is arranged on the farmer's field, a split-plot in a randomized complete block design with three replications. Treatments produced significant results for plant height. Panicle length and grain yield but thousands grains weight was not significant. Result showed that application of half of recommended 60-40-40 + organic manures 10 t ha-1 produced significantly higher value for grain yield and good for quality lance rice.

Landrace rice genotypes AG4 were evaluated inTri Ton, Tinh Bien, AnGiang Province with three replications in a field experiment during 2019 to 2020. The analysis revealed significant differences among the genotypes against all the characters studied. In general, phenotypic variance is higher than the corresponding genotypic variance for all the characters studied. AG4 rice is considered as the unique landrace varietal group because of its aroma and superior grain quality.To confirm the presence or absence of fragrance in AG 4,a set of 11 lines was phenotypedby using gas chromatographic separation to quantify 2AP content in milled rice samples. KOH tested and PCR method with two directives RM223 and FMU1-2 are recorded to select the lines with the best fragrance followed by line7, 10 ,14 and 20.The shape is determined by the length and width ratio.From shape evaluation, length and width ratio of AG4 are high. Level of chalkiness is. There are mostly low contents on AG4, when doing rice quality analysing. It is the evidence for the deliciousness on rice. Milling quality determines the final yield and fracture rate of milled rice. Recorded line 7 for high milling rate is over 50%. Protein content of rice varieties ranges from 6.9 to 8.6%. Lines 7 and 56 have the highest protein content (8.5-8.6%). Characters like number of panicles per plant, panicle weightg, number of grains per panicle, and grain yield recorded are high. Grain yield analysis revealed significant differences among lines. Selected AG4, lines number 7 can be used in breed selection program in the nearest future to provide the local need.

Salinity affects rice growth in all growth stages, with the seedling and reproductive stages being the most sensitive. Genetically improving salt tolerance of rice is an important objective of rice breeding programs. Hence, mapping quantitative trait loci (QTL) will be useful for marker-assisted selection in rice breeding programs. An advanced backcross population (BC2F2) was developed with the parents included OM5629 as a donor of salt tolerance and OM7347 as a recurrent parent with good quality traits and drought tolerance. Molecular markers associated with both qualitative and quantitative trait loci (QTL) salt tolerance were identified by using 416 polymorphic SSR markers. QTLs, associated with stress tolerance at EC = 15 dS/m at seedling stage, detected from the BC2F2 population of OM7347/OM5629, were located on chromosomes 1 and 3. Three QTLs were identified at the intervals of RM3252-S1-1 - RM10694, RM3740-RM5336 and RM11125-RM9 with genetic distance of 4.4, 4.5 and 18 cM on chromosome 1, respectively. Two QTLs at the intervals of RM3867-RM6959 and RM6876-RM4425 with genetic distance of 4.5 and 18.0 cM on chromosome 3, respectively. One QTL on chromosome 5 was detected at the interval of RM874 - RM10359, it was associated with salt stress tolerance under EC = 8dS/m at vegetative stage. Three QTLs at the regions of RM1324-RM2412, RM1185-RM24, and RM1282-RM2560 on chromosome 1, and one QTL of RM453-RM511 on chromosome 12, were related to salt tolerance under EC = 8dS/m at reproductive stage. Two tightly linked markers as RM3252-S1-1 and RM3867, were exhibited their effectiveness in identification of salt tolerance genotypes in BC3F6 population of OMCS2000/ Pokkali. The identification of new QTLs associated with salt tolerance will provide important information for the functional analysis of rice salinity stress.