Estimates Of Genetic Variance Component Of An Equilibrium Population Of Corn

There are abundant maize populations in Hardy-Weinberg equilibrium, which can be used as source of gene to develop either a hybrid variety or an open pollinated variety. Genetic parameters of a population, such as additive genetic variance and variance due to dominance which can be estimated using North Carolina Design I, were used to decide a breeding method to be applied. The objectives of this research were to estimate the genetic variance component of important quantitative traits in an equilibrium corn population and to decide the best method to develop the population. The research was conducted at Agricultural Station of Agriculture Faculty, Gadjah Mada University, in 2012 which was carried out in two steps: to develop half-sib and full-sib families and to evaluate both families in randomized complete block design with three replications. The data was subjected to analysis of variance, and was followed by estimation of genetic variances. The additive variance of ear length and ear diameter of the corn population was greater than dominance variance. In contrary to kernel weight/ear, the dominance variance was greater than additive variance. So based on kernel weight/ear, the Hardy-Weinberg equilibrium corn population can be developed through inbreeding to form a hybrid variety

Pengujian Stabilitas Membran Sel Dan Kandungan Klorofil Untuk Evaluasi Toleransi Suhu Tinggi Pada Tanaman Kentang

Cekaman suhu tinggi memengaruhi proses fisiologis tanaman dan stabilitas membran sel. Penelitian dilakukan untuk mengevaluasi sifat toleran terhadap cekaman suhu tinggi pada kentang dengan menguji stabilitas membran sel dan kandungan klorofil. Pengujian terhadap 13 varietas dan tujuh klon kentang dilakukan di Laboratorium Kultur Jaringan dan Laboratorium Fisiologi Tanaman, Balai Penelitian Tanaman Sayuran dari Bulan April sampai Juli 2012. Uji stabilitas membran sel dilakukan melalui pengukuran pelepasan elektrolit akibat kerusakan membran sel oleh suhu tinggi, sedangkan kandungan klorofil diukur menggunakan metode spektrofotometri. Pengujian menggunakan rancangan acak lengkap dengan dua kali ulangan. Hasil penelitian menunjukkan bahwa varietas Cipanas, serta klon CIP 390663.8, CIP 392781.1, CIP 394613.139, dan CIP 395195.7 (planlet dan tanaman di rumah kasa), Merbabu 17 (planlet), serta klon CIP 394614.117 dan varietas Ping 06 (tanaman di rumah kasa) mengalami kerusakan membran sel di bawah 40%. Cekaman suhu tinggi juga menyebabkan penurunan kandungan klorofil. Penurunan total klorofil yang tinggi (60,20–69,15%) terjadi pada varietas Erika, Manohara, Margahayu, Repita, dan Tenggo, serta klon N.1. Klon CIP 395195.7 dan varietas Ping 06 memiliki kandungan total klorofil yang tinggi pada kondisi suhu tinggi, dengan penurunan total klorofil akibat suhu tinggi yang kecil. Genotip-genotip yang memiliki persentase kerusakan membran sel kecil, kandungan total klorofil yang tinggi, dan penurunan kandungan klorofil yang kecil, diduga memiliki sifat toleran terhadap cekaman suhu tinggi

Utilization of Cpdna Sequences to Identify 15 Mango Accessions

Information about genetic relationship and genetic diversity are an inevitable need in mango breeding program. Base substitution value, genetic distance and grouping of 15 mango accessions based on accessions in chloroplast DNA (cpDNA) among 15 mango accessions were assessed. The samples were originated from Mango Germplasm, Cukur Gondang Research Station of Indonesian Tropical Fruits Research Institute, Pasuruan, East Java. Sequencing of Chloroplast DNA was used to obtain nucleotide sequence data. Paired specific primer rpl20 F - rps12 R and atp F - rbcL R were used for amplification of non-coding area of mango DNA chloroplast and sequencing processes as well. All data were analyzed using Software MEGA 6. The result showed that total numbers and nucleotide base sequences varied among all accessions. All accessions were grouped in five different clusters that might be used as source of parental breeding

Hubungan Antara Hasil Dan Komponen Hasil Wijen (Sesamum Indicum L.) Pada Generasi F1 Dan F2 Persilangan Sbr2, Sbr3, Dan Dt36

Dalam program pemuliaan tanaman wijen, informasi keragaman genetik dan hubungan antarsifat sangat penting untuk menentukan keberhasilan seleksi. Penelitian yang bertujuan untuk mempelajari keragaman genetik dan hubungan antara komponen hasil dan hasil wijen pada generasi F1 dan F2 persilangan Sbr 2, Sbr 3, dan Dt 36 telah dilaksanakan dari bulan November 2012 sampai dengan Februari 2013 di Padangan, Sitimulyo, Piyungan, Bantul, Yogyakarta. Penelitian menggunakan rancangan acak lengkap (RAL) dengan tiga ulangan. Bahan tanam yang digunakan adalah benih tetua, F1, dan F2 hasil persilangan antara Sbr 3 x Sbr 2, Sbr 3 x Dt 36, Sbr 2 x Dt 36, dan resiproknya. Benih bulk hasil persilangan ditanam secara rapat dalam baris pada petak-petak yang berukuran 4 x 1 m. Pengamatan dilakukan pada parameter tinggi tanaman, jumlah cabang, jumlah polong, berat polong, berat biji, jumlah ruas, panjang ruas, umur berbunga, umur panen, dan berat 1.000 biji. Hasil penelitian menunjukkan bahwa komponen hasil yang memiliki keragaman genetik besar adalah berat biji per tanaman (68,437%), berat polong (40,532%), jumlah cabang (33,251%), jumlah polong (30,269%), dan tinggi tanaman (21,256%). Nilai heritabilitas yang tinggi terdapat pada tinggi tanaman (65,52%) dan umur panen (55%). Komponen hasil yang memiliki korelasi nyata terhadap hasiladalah jumlah cabang, jumlah polong, berat polong, dan umur berbunga, sedangkan yang berpengaruh langsung terhadap hasil wijen adalah jumlah cabang dan berat polong. In sesame breeding program, information about genetic variations and relationships ammongs characters is very important to determine the success of line selection. Studies about correlation between yield and yieldcomponents of F1 and F2 from crosses of Sbr 2, Sbr 3, and Dt 36 was conducted on November 2012 to February 2013 in Padangan, Sitimulyo, Piyungan, Bantul, Yogyakarta. The treatments were arranged in completerandom design (CRD) with three replications. Planting materials used were the seed of parents, F1, and F2 from crossing between Sbr 3 x Sbr 2, Sbr 3 x Dt 36, Sbr 2 x Dt 36, and their reciprocals. Bulk breeding seeds planted in rows in high density to reach maximum populations as the genetic resource in the plots according to its genotypes. The observation was made on plant height, number of branches, number of pods, weight of pods, number of nodes, nodes length, day of flowering, plant maturing age, and 1,000seed weight. The results showed that, components which showed high genetic variation were weight of seeds per plant (68.437%), weight of pods (40.532%), the number of branches (33.251%), number of pods(30.269%), and plant height (21.256%). High heritability values was shown in parameters of plant height (65.52%) and plant maturing age (55%). Yield components which have significant correlation with the yield were number of branches, number of pods, pod weight, and days to flowering, while those have a direct effect on the yield of sesame are the number of branches and pods weight

Survei Polimorfisme Tetua Untuk Pengembangan Panel CSSL Padi (Oryza Sativa L.) Dan Identifikasi Tanaman F1

Raising yield potential of modernindica varieties is essential to meet the increased demand ofrice production. This is due to increased human population,threats of climate change and degradation of agriculturalresources. The use of chromosome segment substitutionlines (CSSL) is more effective for identification of genesthose are useful for improvement of yield potential. The aimsof this study were to observe the morphological traitdifferences between recipient parent (var. Ciherang) andthree candidates of donor parent (var. Fatmawati and newplant type lines, i.e. B12743 and B11143D), to identifypolymorphic SSR markers among them and to verify F1individuals. Ciherang and B11143D showed significantdifferences on flowering time, plant height, flag leaf area,tiller number, productive tiller number, panicle length,spikelet number per panicle and 1,000 grain weight. The rateof SSR marker polymorphisms between Ciherang andB11143D was the highest, where 155 of 513 markers (30.2%)were polymorphic. Marker genotyping using threepolymorphic markers showed that 26 of 27 plants resultedfrom the cross of Ciherang х B11143D were F1. These F1plants could become the basis of CSSL panel that facilitatethe mapping of genes responsible for increasing the yieldpotential

Comparative mapping of quantitative trait loci involved in heterosis for seedling and yield traits in oilseed rape (Brassica napus L.)

Little is known about the genetic control of heterosis in the complex polyploid crop species oilseed rape (Brassica napus L.). In this study, two large doubled-haploid (DH) mapping populations and two corresponding sets of backcrossed test hybrids (THs) were analysed in controlled greenhouse experiments and extensive field trials for seedling biomass and yield performance traits, respectively. Genetic maps from the two populations, aligned with the help of common simple sequence repeat markers, were used to localise and compare quantitative trait loci (QTL) related to the expression of heterosis for seedling developmental traits, plant height at flowering, thousand seed mass, seeds per silique, siliques per unit area and seed yield. QTL were mapped using data from the respective DH populations, their corresponding TH populations and from mid-parent heterosis (MPH) data, allowing additive and dominance effects along with digenic epistatic interactions to be estimated. A number of genome regions containing numerous heterosis-related QTL involved in different traits and at different developmental stages were identified at corresponding map positions in the two populations. The co-localisation of per se QTL from the DH population datasets with heterosis-related QTL from the MPH data could indicate regulatory loci that may also contribute to fixed heterosis in the highly duplicated B. napus genome. Given the key role of epistatic interactions in the expression of heterosis in oilseed rape, these QTL hotspots might harbour genes involved in regulation of heterosis (including fixed heterosis) for different traits throughout the plant life cycle, including a significant overall influence on heterosis for seed yield

A Dynamic and Complex Network Regulates the Heterosis of Yield-Correlated Traits in Rapeseed (Brassica napus L.)

Although much research has been conducted, the genetic architecture of heterosis remains ambiguous. To unravel the genetic architecture of heterosis, a reconstructed F2 population was produced by random intercross among 202 lines of a double haploid population in rapeseed (Brassica napus L.). Both populations were planted in three environments and 15 yield-correlated traits were measured, and only seed yield and eight yield-correlated traits showed significant mid-parent heterosis, with the mean ranging from 8.7% (branch number) to 31.4% (seed yield). Hundreds of QTL and epistatic interactions were identified for the 15 yield-correlated traits, involving numerous variable loci with moderate effect, genome-wide distribution and obvious hotspots. All kinds of mode-of-inheritance of QTL (additive, A; partial-dominant, PD; full-dominant, D; over-dominant, OD) and epistatic interactions (additive × additive, AA; additive × dominant/dominant × additive, AD/DA; dominant × dominant, DD) were observed and epistasis, especially AA epistasis, seemed to be the major genetic basis of heterosis in rapeseed. Consistent with the low correlation between marker heterozygosity and mid-parent heterosis/hybrid performance, a considerable proportion of dominant and DD epistatic effects were negative, indicating heterozygosity was not always advantageous for heterosis/hybrid performance. The implications of our results on evolution and crop breeding are discussed