Heterosis, Combining Ability and Yield Prediction in Hybrids From Local Maize Inbred Lines

Studies were conducted to identify and select for superior maize inbred lines based on their performance per 5e, and to evaluate their performance and combining ability in all possible crosses. Performance and heterosis of the single crosses were evaluated at two locations, in Universiti Pertanian Malaysia, Serdang. Furthermore, some promising double cross hybrids developed from the potential single crosses were also evaluated for performance and for comparison with the predicted. In general , most of the inbred lines exhibited poor performances due to inbreeding effects after successive generations of selfing, but some were however, found to have high potential for use in hybrid production. Hy-58, Hy-59 and Hy-60 were identified as the best performing F1 single-cross hybrids at both locations, with grain yields of 3703.7 kg/ha, 3940.7 kg/ha and 3451.9 kg/ha, respectively, at Field 2; 5659.3 kg/ha, 572 5.9 kg/ha and 5948.1 kg/ha, respectively, at Share Farm; and 468 1.5 kg/ha, 4833.3 kg/ha and 4700.0 kg/ha, respectively, in the locations combined. In general, hybrids that produced high yields were those formed between inbred parents that were themselves high yielding and from genetically diverse population sources. High heterosis was shown by grain yield, ear weight and grain weight per ear, moderate heterosis by number of kernels per row, ear height, plant height and ear length, while low heterosis was shown by ear diameter, number of kernel rows per ear, 100-grain weight and shelling percentage. Maturity characters showed negative heterosis, indicating earliness of the hybrids

Performance and yield predictions in double cross hybrids of tropical grain maize

The use of double cross hybrids in maize was suggested to overcome the problem of seed production related to single cross resulting from low vigor and yield associated with the inbred parents. Double cross hybrids were known to perform quite well under a wide range of environmental conditions. As a part of an ongoing grain maize improvement program at Universiti Putra Malaysia, the best performing inbred lines were selected and crossed to produce single crosses. These single crosses were further used to produce some double cross hybrids. In this study, the performance of ten selected double cross hybrids was evaluated at two environments in the research areas of Universiti Putra Malaysia. The predicted performance of these double cross hybrids was also compared with the actual, using the method based on the mean values of non.parental single crosses. The best performing double cross hybrids, DC-26 and DC-34 were found to have high yields at both environments as well as in the combined analysis. DC-26 and DC-34 gave mean grain yields of 6125.0 and 5917.8 kg/ha respectively, at Field 2, 5648.9 and 5676.2 kg/ha respectively, at Share Farm, and 5887.0 and 5797.0 kg/ha respectively, in the combined analysis. From the correlation analysis, the actual and the predicted performances of the double cross hybrids were found to be in good agreement at each location and locations combined (r = 0.38, 0.46 and 0.27, respectively, at Field 2, Share Farm and at the two locations combined), implying that the method used for yield predictions in the crosses was appropriate

COMBINING ABILITY AND HETEROSIS OF CHILLI (Capsicum annuum) RESISTANCE TO ANTHRACNOSE

Anthracnose (Colletotrichum acutatum) is considered as the major disease in chilli. Resistant variety isimportant for controlling infection of disease, since fungicide application and other cultural controlled methodswere not effective. The aim of this research was to estimate combining ability and heterosis of chilli resistanceto anthracnose. Set population of half diallel crosses which involved 6 parents and 15 crosses with C. acutatumisolate BKT 04 were used in this experiment. Mature green fruit were inoculated using a microinjection method.Disease resistant percentage and lesion diameter were used for estimating of combining ability. Disease incidenceand lesion diameter were used for estimating heterosis. General combining ability of IPB C15 was high for diseaseresistance percentage and lesion diameter. Specific combining ability of IPB C15 x IPB C9 was high for diseaseresistance percentage and specific combining ability of IPB C15 x IPB C10 and IPB C4 x IPB C2 were high forlesion diameter. Negative heterosis was expected in disease resistance traits; IPB C15 x IPB C9 had negativeheterosis for disease incidence and IPB C10 x IPB C9 had negative heterosis for lesion diameter

PENAPISAN GENOTIPE CABAl (Capsicum annuum L.) TOLERAN A\u27-UMINIUM BERDASARKAN PERBEDAAN PANJANG AKAR PADA FASE VEGETATIF = THE SCREENING OF CHILI TOLERANT-GENOTYPES TO ALUMINUM BASED ON THE ROOTS LENGTH IN VEGETA TIVE PHA

The aims of the research were to determine- index of AI saturation causing AI stress in chili and to identify chili genotypes tolerance to AI using root bioassay. The research had been carried out in University Farm of IPB in Cikabayan from September 2005 to January 2006. The media was Ultisol from Gajrug (Lebak, Banten) in polybags. Twenty genotypes of chili were tested at different level of AI saturation (0.77, 15.92, 31.96, 60.85 and 83.48%) by adding lime in different treatments (18.33, 13.75, 9.16, 4.58 and 0 g CaCO/kg soil, respectively). The tolerance to aluminum was determined by relative root length (RRL) value, i.e. the root length at AI-stress condition were compared to that without AI-stress condition. Screening results showed that 5 genotypes were potentially tolerant to AI, namely PBC 619, Jatilaba, Cilibangi 5, Jayapura dan Marathon3 genotypes were moderate (Randu, Karo and PBC 473)and 12 genotypes were sensitive to AI (Cilibangi 3, PBC 549, Tit Bulat, Helm, Bengkulu, PBC 065, PBC 593, Tampar, Tit Super, Cilibangi 6, PBC 584 and Cilibangi 1)

Combining Ability of Several Introduced and Local Chilli Pepper (Capsicum annuum L.) Genotypes and Heterosis of the Offsprings

The objective of the study was to identify the combining ability of several introduced and local chilli genotypes and heterosis effects of their offsprings, as a result of the hybridisation process. This information will be used for production of hybrid varieties. The study was conducted from November 2006 to May 2007 at Tajur experimental station, Bogor, West Java, Indonesia. The fi ve parents with their ten F1 hybrids were evaluated in a randomized complete block design (RCBD) with three replications. The results showed that hybrid IPB C15 x IPB C19 had the highest fruit weight per plant, and hybrid IPB C8 x IPB C19 had the highest heterosis for this character. Hybrid IPB C8 x IPB C15 has highest number of fruits per plant and showed heterosis effects. Crosses among introduced and local genotypes resulted a high heterosis values. Additive variance of weight and number of fruits per plant were greater than the dominant variance. IPB C19 had the best general combining ability for fruit weight per plant character. Keywords: capsicum, combining ability, heterobeltiosis, heterosi

Heterosis dan Daya Gabung Karakter Agronomi Cabai (Capsicum annuum L.) Hasil Persilangan Half Diallel

<!-- /* Font Definitions */ @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1610611985 1073750139 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin-top:0cm; margin-right:0cm; margin-bottom:10.0pt; margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:Calibri; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:"Times New Roman"; mso-ansi-language:IN; mso-no-proof:yes;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> The objective of this research was to study heterosis and heterobeltiosis effects of fi  fteen chili genotypes (Capsicum annuum L.), the general combining ability (GCA) and specifi  c combining ability (SCA) of six chili inbred lines through half diallel crosses. The experiment was conducted from November 2008 to June 2009 using a Randomized Complete Block Design with three replications at IPB experimental fi  eld, Leuwikopo, Darmaga. Heterosis values were predicted based on the average values of their parents whereas heterobeltiosis were predicted based on the average values of the highest parents. Analyses GCA and SCA were based on the Griffi  ng’s fi xed model of diallel design method II. Genotype IPB C2 had  the highest GCA for fruit weight and fruit length. Genotype IPB C15 had the highest GCA for yield per plant and percentage of marketable fruit. Hybrid IPB C2 x IPB C14 and IPB C9 x IPB C14 had the highest heterosis, heterobeltiosis, and SCA for all fruit characters and yield per plant. Keywords: chili, hybrid, heterobeltiosis, yield