Agro-morphological characterization based genetic diversity of Indonesian local rice germplasm

The present study was carried out to characterize 103 Indonesian local rice germplasm on the basis of 20 agro-morphological traits. The local rice germplasm originated from Riau and Jambi province in Sumatera island. Principal Component Analysis (PCA) was used to analyzed 11 quantitative data. PCA explained the genetic diversity of the rice germplasm accession. Most of the morphological characters showed variation in different accession. PC1 and PC2 explained about 32.5% and 22.1% of the variability, respectively. PCI and PC2 mostly related with traits such as productive tiller number (PTN), vegetative tiller number (VTN), plant height (PH), and culm length (CL). PCA-Biplot showed accession from Jambi and Riau manage to be separated, even though the PCA percent is only 54.6%. Accession originated from Riau marked by number of tillers (PTN, VTN), and grain weight (GW) traits. Based on cluster analysis, rice germplasm grouped in to 4 main clusters. Most of the accession from Jambi and Riau grouped in the same cluster, which is cluster I. Whereas eight local accessions from Riau grouped in the same cluster separately (cluster II). Two accession which are Padi Jarum (Acc 2711) and Ketan Hitam (Acc 9300) are individually, separated from others.

Heading Uniformity: A New Comprehensive Indicator of Rice Population Quality

Productive tiller percentage (PTP) is the only available comprehensive indicator of rice population quality. However, productive panicle number (PN) has a great effect on its characterization accuracy. Panicle exsertion is an important but difficult to describe morphological index; therefore, it cannot be easily determined. The aims of this study were to develop heading uniformity (HU), which describes the difference in the degree of rice panicle exsertion, as a new comprehensive indicator by designing a representative sampling and calculation method and exploring the relationship between HU and yield components. HU first decreased then increased after initial heading, exhibiting a single-valley curve. Adequate HU was obtained by panicle sampling on day two or three (panicle N fertilizer proportion ≤40 or >40%) after initial heading. The explanatory power of PTP for grain yield variance was markedly insufficient in low- and high-PN rice populations. Compared with the percent contribution of PTP to grain yield variance (12.32–41.26%), that of HU (49.02–61.93%) was greater and more stable across rice populations of different PNs. Moreover, HU showed fewer interannual variations, despite large interannual differences in weather and soil conditions. Hence, HU may have applications as a comprehensive indicator of rice population quality.

SELECTION OF SHORT STATURE AND EARLY MATURING BADSHAH BHOG IN M2 FROM GAMMA RAY IRRADIATION

Badshah Bhog is a non basmati aromatic traditional rice cultivar. which is not widely cultivated due to some unfavourable traits which were relatively high plant height, late maturity and low average yield. By the utilization of gamma ray irradiation in plant breeding attempted to overcome such problems in crops. The objective of this research is to observe and select M2 mutants of Badshah Bhog from gamma ray irradiation and obtain early maturing short stature plants. The research was conducted by Line sowing method. Established experimental plots for every irradiation doses and comparing the treatment result with the control to identify the effect of irradiation on the growth of Badshah Bhog. The result showed that there have been several plants with potential mutant traits supported the positive and negative character of every individual. The irradiated dose of 300 Grays has the shortest maturity duration of 131 days with the highest productive tiller of 6.67 but very low as compared to control. The irradiated dose of 400 Grays has the shortest Plant height of 97.8 cm. The plant yield of mutant lines in the present study was not affected significantly in any direction which could due to occurrence of polygenic mutations with ‘plus’ and ‘minus’ effect equally distributed. Together with short stature plants also plants bearing double spikelet at tip and mid region of panicle observed.

KAJIAN VARIABILITAS GALUR-GALUR PADI GOGO PADA LAHAN KERING MASAM

[VARIABILITY STUDIES OF UPLAND RICE LINES ON AN ACIDIC SOIL]. Suscessful upland rice breeding program to produce productive and adaptive to acid soil is dependent upon the extent of genetic variability of the breeding materials. Objectives of this study were to estimate the genetic variability, phenotypic and genotypic coeficient of variations, heritability, genetic advance, and correlation of five traits observed from dari 298 upland rice lines and five checks varieties. A field field experiment arranged in an augmented design was conducted at the Tamanbogo Experimental Station in Lampung 1 MT 2019.. The results of the analysis of variance showed that there was diversity among lines, resulting in differences in appearance on plant height, number of productive tillers, and yields. High heritability, genetic advancement, and high correlation on the number of productive tiller indicate that this character is a selection criteria so that selection can be done in an effort to improve these characters

Genetic Basis of Tiller Dynamics of Rice Revealed by Genome-Wide Association Studies

A tiller number is the key determinant of rice plant architecture and panicle number and consequently controls grain yield. Thus, it is necessary to optimize the tiller number to achieve the maximum yield in rice. However, comprehensive analyses of the genetic basis of the tiller number, considering the development stage, tiller type, and related traits, are lacking. In this study, we sequence 219 Korean rice accessions and construct a high-quality single nucleotide polymorphism (SNP) dataset. We also evaluate the tiller number at different development stages and heading traits involved in phase transitions. By genome-wide association studies (GWASs), we detected 20 significant association signals for all traits. Five signals were detected in genomic regions near known candidate genes. Most of the candidate genes were involved in the phase transition from vegetative to reproductive growth. In particular, HD1 was simultaneously associated with the productive tiller ratio and heading date, indicating that the photoperiodic heading gene directly controls the productive tiller ratio. Multiple linear regression models of lead SNPs showed coefficients of determination (R2) of 0.49, 0.22, and 0.41 for the tiller number at the maximum tillering stage, productive tiller number, and productive tiller ratio, respectively. Furthermore, the model was validated using independent japonica rice collections, implying that the lead SNPs included in the linear regression model were generally applicable to the tiller number prediction. We revealed the genetic basis of the tiller number in rice plants during growth, By GWASs, and formulated a prediction model by linear regression. Our results improve our understanding of tillering in rice plants and provide a basis for breeding high-yield rice varieties with the optimum the tiller number.

Genetic Basis of Tiller Dynamics of Rice Revealed by Genome-Wide Association Studies

Background: Tiller number is the key determinant of rice plant architecture and panicle number and consequently controls grain yield. Thus, it is necessary to optimize the tiller number to achieve the maximum yield in rice. However, comprehensive analyses of the genetic basis of tiller number, considering the development stage, tiller type, and related traits, are lacking.Results: We sequenced 219 Korean rice accessions and constructed a high-quality single nucleotide polymorphism (SNP) dataset. The tiller number at different development stages and heading traits involved in phase transitions were evaluated. By a genome-wide association study (GWAS), we detected 20 significant association signals for all traits. Five signals were detected in genomic regions near known candidate genes. Most of the candidate genes were involved in the phase transition from vegetative to reproductive growth. In particular, HD1 was simultaneously associated with the productive tiller ratio and heading date, indicating that the photoperiodic heading gene directly controls the productive tiller ratio. Multiple linear regression models of lead SNPs showed coefficients of determination (R2) of 0.49, 0.22, and 0.41 for the tiller number at the maximum tillering stage, productive tiller number, and productive tiller ratio, respectively. Furthermore, the model was validated using independent japonica rice collections, implying that the lead SNPs included in the linear regression model were generally applicable to tiller number prediction.Conclusions: We revealed the genetic basis of tiller number in rice plants during growth by a GWAS and formulated a prediction model by linear regression. Our results improve our understanding of tillering in rice plants and provide a basis for breeding high-yield rice varieties with the optimum tiller number.

GENETIC VARIABILITIES OF AGRONOMIC TRAITS AND BACTERIAL LEAF BLIGHT RESISTANCE OF HIGH YIELDING RICE VARIETIES

<p class="abstrakinggris">Hundred of high yielding and bacterial leaf blight (<em>Xanthomonas oryzae</em> pv. <em>oryzae, Xoo</em>) resistant rice varieties released since the 1960s are important sources of genetic materials for exploring superior genotypes. The study aimed to evaluate the genetic resistance of 177 rice varieties to <em>Xoo</em> and their agronomic traits. The evaluations were conducted at the Indonesian Center for Rice Research Experimental Station during the wet season (December 2015-March 2016). The bacterial leaf blight resistance was evaluated for <em>Xoo</em> pathotypes III, IV, and VIII using the clipping method. The genetic variation among genotypes was categorized as low (0–10%), medium (10–20%), and high (&gt;20%), whereas the heritability was categorized as low (0-30%), medium (30-60%), and high (&gt;60%). The variability of resistance to <em>Xoo</em> pathotypes, grain yield, and spikelet fertility was low, while the variability of plant height, productive tiller number, filled grain, and total spikelet was medium, and the variability of unfilled grain number was high. The 29 varieties were categorized as superior based on their agronomic traits or resistance to <em>Xoo</em> pathotypes. In conclusion, Batutegi and Fatmawati were superior in the total spikelet number, while Rojolele and Inpari 2 were supreme in the thousand-grain weight. Dodokan had a very short maturity, and Inpari 24, Conde, Kalimas, Angke, Inpari 17, and Inpara 8 had the highest resistance to <em>Xoo</em> pathotypes. The study implies that the identified rice superior genotypes could be used as genetic materials to design cross combinations for higher yield potential and BLB resistance varietal improvement.</p>

Respon Pertumbuhan dan Hasil Padi (Oryza sativa L.) terhadap Cekaman Suhu Tinggi

Global climate change will imply to increase in atmospheric temperature, which can affect the sensitive stadia and decrease rice yield. The objective of this research was to study the growth and production of rice varieties under hightemperature stress. This research was conducted using a split-plot design under partitioned polyethylene house in order to create temperature differences among main-plots. The partitioned treatment successfully increased by 1.7 °C of average temperature with a maximum temperature of 35.0 °C (T1) and 37.6 °C (T2). Rice varieties, namely IR64, Ciherang, IPB-3S, Way Apo Buru, Jatiluhur, Menthik Wangi and Silugonggo were randomized as sub-plot. The results showed that increasing temperature had no significant effect on plant height, tiller number, SPAD-value, leaf area index, and crop growth rate, but significantly decreased 1,000 grains weight by 4.57% and harvest index by 20%. The interaction between temperature and varieties significantly affected a percentage of a productive tiller and partially filled spikelets. Ciherang variety produced the lowest percentage of productive tillers on T2 by 57.6%. Way Apo Buru variety produced the lowest percentage of partially filled spikelets on T2 by 3.01%.

Evaluation of finger millet [Eleusine coracana (L.) Gaertn.] accessions using agro-morphological characters

The study was conducted at village level in-situ center, Jawhar block of Palghar district of Maharashtra during the year 2017 and 2018 to characterize 20 accessions of finger millet. Data was collected on morphology, plant growth and yield contributing characters. Traits like erect growth habit (80 percent); semi-compact ear (60 percent); partially enclosed seeds by glumes (60 percent) and light brown colour of seed (75 percent) was found dominant among studied accessions. The results indicated that studied landraces exhibited variability in finger number (6 to 14), finger length (7 to 16 cm) and maturity days (85 to 117). The results of study also showed that productive tiller number was most varied trait (29.37 percent), followed by ear head length (21.98 percent) and finger number (19.42 percent). Among the studied traits, finger width showed the lowest variation (7.65 percent). Analysis of variance showed that all the characters were highly significant among the accessions. This potential gene pool needs to be conserved and may be explored for crop improvement in future.

PERTUMBUHAN DAN HASIL GALUR-GALUR F4 PADI RAWA PADA RAWA LEBAK

[GROWTH AND YIELD OF F4 SWAMP RICE LINES ON LINE SWAMP]. Growth and yield of swamp rice are depending on the plant ability to adapt in swampy agro-ecosystem which characterized by several limiting factors. This study was addressed to evaluate the growth and yield characteristics of six lines of swamp rice bred for the development of high-yielding rice varieties best suited for swamp land production. Evaluation was conducted in a pot experiment using UBPR2, UBPR3,UBPR6, UBPR7, UBPR9, and UBPR10 as planting materials. These lines were the F4 generation derived from crosses involving local Bengkulu swamp rice varieties. Observations were made on 13 plant characteristics, dry matter accumulation, leaf area ratio, specific leaf weight, net assimilation rate, plant height, productive tiller number, heading date, maturity date, panicle length, grain number per panicle, percent of filled grain, and plant yield (the grain weight per clump). The collected data were subjected to analysis of variance and least significant difference test at 5% level. Results indicated that all lines physiologically exhibited similar growth patterns, excepting the capability of accumulating dry matter at 40 dap. In this case, UBPR6 produced the highest dry matter accumulation (24.34 g). Based on the morphological performances, significant variations among the lines were observed on most of the observed characteristics, except on productive tiller number and panicle length UBPR10 was the line produced the tallest plant stature (160.72 cm), UBPR2 was the earliest flowering and maturing line (76,33 and 111 dap), whereas UBPR6 was the line produced the highest grain number per panicle (212,2), percent of filled grain (95%), and plant yield (82.50 g per clump).