Perbandingan Pemillhan Berulang Ringkas dan Pemilihan Berulang Salingan Penuh-Sib ke Atas Dua Populasi Jagung Manis

Satu program pemilihan ke atas populasl jagung manis Bakti 1 dan Manis Madu telah dijalankan di Ladang Universiti Pertanian Malaysia dengan menggunakan dua kaedah pemilihan berulang, iaitu pemilihan berulang ringkas berasaskan prestasi progeni Sl dan pemilihan berulang salingan penuh-sib. Objektif utama kajian ini ialah untuk menghasilkan populasi-populasi maju dari populasi-populasi asal yang digunakan. Objektif khusus ialah untuk menentukan keberkesanan secara relatif dua kaedah pemilihan tersebut, menentukan pengawalan genetik dan kebolehwarisan luas beberapa ciri penting, menganalisis korelasi antara hasil dan komponen-komponen hasil di dalam populasi penyendirian Bakti 1 dan Manis Madu, dan menganalisis kesan pemilihan. Tiga ciri-ciri pertumbuhan pokok dan sembilan ciri-ciri hasil dan komponen hasil telah dinilai

Genetic inheritance of multiple traits of blast, bacteria leaf blight resistant and drought tolerant rice lines

Rice (Oryza sativa L.) is a cereal and staple food crop of over half of the world’s population. Blast, bacteria leaf blight and drought stresses affect yield of rice drastically ranging from 1-100% loss depending on the severity of disease and water deficit condition. Resistance and tolerance high yielding varieties of blast (Putra1) and drought (MR219 IR99784-156-137-1-3) respectively and also IRBB60 (bacteria leaf blight) were used. The research considered the genetic inheritance of the new improved lines and their interactions. Pedigree breeding method was used to develop two single, double and three-way (and reciprocal) crosses through marker-assisted selection. Southern blot analysis was used to determine success of introgression of resistance/tolerance genes/QTLs and selection, also validated by phenotyped results. Agro-morphological and yield parameters of the various populations were analysed. The results indicated levels of significant differences amongst and between treatments for non-drought stress (NS) and reproductive drought stress (RS) and their interactions. There were significant variation among parents and improved lines on some traits in NS treatment, but RS significantly affected parameters of DF, FFG, YM and most especially the susceptible parent, while the improved lines were tolerant.  Significant interactions was recorded (P≤0.05) between treatment and variety (Trt*Var.) on PL, T, FFG and GLW. Cluster analysis and PCA of relationship among the 9 traits in the two treatments revealed that each of single, double and three-way (and reciprocal) crosses had good lines either under NS and RS.

Optimizing plant spacing for modern rice varieties

The experiment was performed under sub-tropical condition (24.75 N and 90.50 E) during the period of December 2011 to May 2012 to evaluate the effect of spacing on assimilate availability, yield attributes and yield of modern rice varieties. Four modern rice cultivars BINAdhan5, BINAdhan6, Iratom and BRRIdhan29 were sown with three spacing viz., 20 cm×20 cm, 20 cm×15 cm and 20 cm×10 cm. The experiment was laid out in a split-plot design with four replicates. Wider spacing of 20 cm×20 cm had shown superior performance in respect of all morpho-physiological and yield components, which resulted in the highest grain yield (8.53 t ha-1). In contrast, closer spacing of 20 cm×10 cm showed inferior performance in respect of above studied parameters and produced the lowest grain yield (6.47 t ha-1). Among the cultivars, BRRdhan29 and BINAdhan6 performed the best regarding yield attributes and produced the highest grain yields (7.53 and 7.72 t ha-1, respectively). The spacing of 20 cm×20 cm may be recommended for cultivation of high yielding modern rice instead of recommended spacing of 20 cm×15 cm after few more trials in farmers' field

Oil palm (e. guineensis) seed dormancy type and germination pattern

This study aimed to evaluate seed dormancy type and germination pattern for oil palm seeds. Physical dormancy tests included imbibition of intact, scarified and heat-treated seeds to determine percentage of mass increase over time. Seeds were stored at room temperature for 32 weeks to monitor embryo growth and seed germination. Physiological dormancy was evaluated by pre-soaking the seeds in 150 mg L-1 GA3. Results showed that the seeds were unable to imbibe water. Morphological tests on seeds at room temperature indicated that an embryo length of 3.64 or 3.03 mm was required to initiate germination in tenera × tenera (T × T) and dura × pisifera (D × P) seeds, respectively. Heat treatment accelerated embryo growth, regardless of treatment duration. Application of exogenous GA3 did not significantly increase germination. The seeds recorded higher germination at 30°C compared with room temperature. Oil palm embryo growth potential increases with time to overcome mechanical resistance of the endosperm micropylar region. The embryo growth (length) greater than 13% is required to commence germination. Results indicate that oil palm seeds have a combination of both morphological and physical dormancy

Inbreeding depression and heterosis in sweet corn varieties Manis Madu and Bakti-1

S1 and full-sib progeny families developed from selfing and crossing between Manis Madu and Bakti-1 sweet corn varieties were evaluated to estimate inbreeding depression and heterosis in the populations. Selfing has caused a significant decrease in the measurements of all characters taken in both selfed populations, except for days to tasseling which has shown an increase. Midparent heterosis estimates for the characters evaluated ranged from -2.83% to 22.34% for the Manis Madu X Bakti-1 cross progeny population (MMB1), and from -2.65% to 16.57% in the Bakti-1 X Manis Madu cross progeny population (B1MM). The two varieties revealed good potential to be used as parents for crosses between improved populations or inbred lines developed from them

Heritability and Response to Recurrent Selection in Two Sweet Corn Varieties

One cycle of simple and full-sib reciprocal recurrent selection programme was conducted on two sweet corn varieties, Manis Madu and Bakti-1, at Universiti Pertanian Malaysia. The objectives of the study were to compare the response to the two selection procedures, and to estimate heritability of some important characters in the two populations. The presence of higher genetic variance in Bakti-1 S1 population (B1S) compared to that of Manis Madu (MMS) showed that B1S1possessed higher genetic variability than MMS. Broad-sense heritability estimates for the characters studied were moderate to high (42.6% to 65. 7%) in the selfed progeny populations, but were low to moderate (20.0 % to 49.2 %) in the crossed progeny populations. After one cycle of selection, simple recurrent selection was found to be more effective in increasing yield in both populations. Simple recurrent selection increased fresh ear yield in Bakti-1 and Manis Madu by 16. 7% and 10.2% respectively, while full-sib reciprocal recurrent selection increased it in Bakti-1 by 5.9 %, but decreased it in Manis Madu by 6.4 %

Yield and bunch quality component comparison between two-way crosses and multi-way crosses of DxP oil palm progenies

Breeding for hybrid DxP oil palm in many commercial seed producers has recently switched from simple two-way crosses to complicated multi-way crosses with the hope of increasing hybrid vigour and thus higher yield potential. The objective of this study was to evaluate the yield potential of the multi-way (MW) crosses as compared to conventional two way (TW) crosses in United Plantations Berhad. A trial was set up in 2004 where 20 crosses of both multi-way and two-way combinations were field planted and evaluated for six years after maturity. Palms were assessed for yield traits and bunch components through bunch analysis. Fresh fruit bunch weight for both types of crosses was significantly different with MW crosses yielding 37.11 tonnes per ha per year as opposed to TW crosses with 36.40. MW crosses had 1.46 tonnes oil per ha per year advantage over TW. High coefficient of variation (CV%) was seen for selected traits such as bunch number (BNO), average bunch weight (ABW), kernel, shell and mesocarp to bunch (KB, SB and MB), oil to dry and oil to wet mesocarp (ODM and OWM), as well as mean fruit weight (MFW). ANOVA showed that replicate (REP), year (Y) and progeny (ID) were significantly different (p≤0.01) for BNO and fresh fruit bunch (FFB) in both crosses but not significant for REP in ABW of TW. REP was not significant for all the traits except ODM whereas ID was significant for all the traits in both TW and MW. Phenotypic and genotypic coefficients of variance (PCV and GCV) were low (<10%) for all the traits in both types of crosses with MW crosses showing higher PCV and GCV in most cases. Heritability for ABW, FFB, KB, oil to bunch (OB), SB and MFW were higher in MW crosses but lower for BNO, fruit to bunch (FB), MB, ODM and OWM compared to TW crosses

Selection of a high yielding soybean variety: Binasoybean-1

Collected 201 soybean [Glycine max (L.) Merrill] germplasm were evaluated for selection of desirable germplasm for registration as variety and/or for future utilization as breeding materials. Among the germplasm, nine were selected on the basis of better field performance considering their seed yield, morphological characters and yield attributes. Results showed that BAU-S/80 produced higher number of pods/plant and its yield was 2516 kg/ha as against 2142 and 2108 kg/ha of the two control varieties, Sohag and BARISoybean-5, respectively. Yield trials of BAU-S/80 were carried out in both rabi and kharif seasons during the period from 2007 to 2010 in selected locations under soybean growing areas of Bangladesh and found to be suitable for cultivation in the farmers' field. BAU-S/80 was found to be moderately resistant to soybean yellow mosaic virus and collar rot diseases, and also showed lower insect infestation than control varieties. On the basis of superior performance of BAU-S/80, Bangladesh Institute of Nuclear Agriculture (BINA) applied for registration to the National Seed Board NSB of Bangladesh. Consequently, the NSB of Bangladesh registered BAU-S/80 as Binasoybean-1 in 2011 for commercial cultivation in Bangladesh

Changes in growth and photosynthetic patterns of oil palm (Elaeis guineensis Jacq.) seedlings exposed to short-term CO2 enrichment in a closed top chamber

Three varieties of oil palm seedlings (Deli Yangambi, Deli Urt, Deli AVROS) were exposed to three levels of CO2 (400, 800, 1,200 μmol/mol) in split plot design to determine growth (net assimilation rate, NAR; relative growth rate, RGR) and photosynthetic patterns of the seedlings under short-term CO2 exposure of 15 weeks. Increasing CO2 from 400 to 800 and 1,200 μmol/mol significantly enhanced total biomass and leaf area, net photosynthesis (A) and water use efficiency (WUE) especially from weeks 9 to 15. By the end of week 15, total biomass increased by 113%, and A and WUE by one- and fivefold, respectively, while specific leaf area decreased by 37%. Both enhanced biomass and A under elevated CO2 were effective in modifying NAR and RGR as shown by high correlation coefficient values (r 2 = 0.68 and 0.72; r 2 = 0.63 and 0.67, respectively), although WUE seemed to have more influence over the NAR (r 2 = 0.97) and RGR (r 2 = 0.93). Neither interspecific preference nor its interaction with CO2 imposed any significant effect on parameters observed. Growth improvement with CO2 seemed able to produce healthy, bigger and vigorous oil palm seedlings, and the technique may have potential to be developed for use to reduce nursery period

Evidence of sibling species between two host-associated populations of brown planthopper, N. lugens (stål) (Homoptera: Delphacidea) complex based on morphology and host–plant relationship studies

Morphological and host–plant relationship studies were conducted to differentiate two sympatric populations of brown planthopper (BPH), Nilaparvata lugens, one from rice (Oryza sativa) and the other from Leersia hexandra, a weed grass. In morphometric studies based on esterase activities, an UPGMA dendrogram using 17 quantitative morphological characters, including stridulatory organs (courtship signal-producing organs) between two sympatric populations of N. lugens, one from rice and the other from L. hexandra, a weed grass revealed that both populations were separated from each other. An out-group, N. bakeri, was found to be completely different from the two sympatric populations of N. lugens. Rice plants were best suited for the establishment of the rice-infesting population, and L. hexandra was a favourable host for the Leersia-infesting population. The individuals derived from one host did not thrive on the other host, as shown by a significant reduction in survival and nymphal development, ovipositional preferences, ovipositional response, and egg hatchability. Therefore, morphological and host–plant relationship studies indicate that rice-associated population with high esterase activities and L. heaxandra-associated population with low esterase activities are two closely related sibling species