Varietal Improvement Research Articles

Increasing Rice Yield through Targeting Genetic Potentials by Rice Types

Bangladesh needs an average rough rice yield of 9.11 t ha-1 by 2050 which can not be achieved equally across all the geographic regions since the country has various ‘rice types’ with varying yield potentials. This paper focuses on strategic innovations for reaching the yield target by refining rice types. Based on rice ecosystems and the pressing needs, we divided rice areas of Bangladesh in 17 different types. We estimated year-wise land areas and allocated achievable yield targets for each of the rice types. Finally, we compared the target yields and the yields of top-yielding rice varieties in Bangladesh by 2020 across the rice types to understand the current status of our varietal improvement programmes. We sorted out how much improvement is needed in each rice types. Among the rice types, cold-tolerant (Northern and Western) was sorted out as the most potential area of rice yield improvement where rice varieties will be released having a yield advantage of 4.04 t ha-1 by 2050. The chronology of next priority areas for high yielding variety development and their target yield advantages in t ha-1 are saline Boro (4.03), Favourable Boro (long duration) (4), cold-tolerant (Haor) (3.83), tidal submergence (3.8), Healthier rice (Boro) (3.58), Favourable Boro (short duration) (3.33), Healthier rice (Aman) (3.3), Favourable Aman (3.23), Flash flood (3.09), upland rice (2.89), Saline Aman (2.8), Healthier rice (Aus) (2.53), Premium quality rice (2.53), drought (2.38), T. Aus (2.05) and deepwater. Combined genetic interventions like population improvement through cyclic breeding, genomic selection, marker-assisted selection, genome editing, genetic transformation, germplasm utilization through genome-wide association study and phenomics, and development of super hybrid rice are being used in the country to attain yield target for different rice types. Bangladesh Rice J. 24 (2): 67-82, 2021

Stability Analysis of Yield and Yield Attributing Traits of Promising Genotypes of Cluster Bean [Cyamopsis Tetragonoloba (L.) Taub.

Background: Cluster bean is originated in India and Pakistan and is characterized as a short day plant. It is a drought tolerant, warm season legume crop, cultivated mainly as rain fed crop in arid and semi-arid regions during rainy season for vegetable, galactomannan gum, forage and green manure. In view of growing demand for its yield, development of new varieties with stable performance over environments is need of the hour.Methods: Twenty five genotypes of cluster bean including one check were evaluated for yield and its attributes in Randomized Block Design with three replications in field investigation during Kharif, 2019 at three agro-climatic Zones of Telangana. G x E interaction and stability analysis of different genotypes across the three environments were worked out as per the model given by Eberhart and Russel (1966).Result: The environments linear were highly significant for all the traits, revealed that the environments were effective in affecting the performance of all the genotypes with respect to cluster bean yield attributing traits. Genotypes IC-9052, IC-10323, IC-10333, IC-103295 and IC-200680 were high yielding and stable under all environments, IC-103295, IC-10323 and IC-9077P1 for higher gum content, IC-10333, IC-28286, IC-103295 and IC-200715 for protein content and genotype IC- 9077-P1 for fibre content were considered as desirable and stable over the environments. The results of the present study could contribute for stable cluster bean varietal improvement in India.

Morphological and Yield Traits of Pole-Type French Bean Genotypes

Understanding the phenotypic variation and association between the grain yield, and other agronomic traits in French bean genotypes is important for its varietal improvement program. Field experiments were conducted during 2018 and 2019 cropping season at Horticulture Research Station, Dailekh, Karnali Province of Nepal to evaluate pole-type French bean genotypes for plant morphological characters, yield and the association between the agronomic traits. Twelve (Bhatte, Chaumase, Dhankute Chhirke, WP Con Bean, White OP, Dhundi Raj, LB-31, LB-37, LB-39, Madhav, Chinese Long, and Trishuli) pole-type French bean genotypes were laid out in a randomized complete block design (RCBD) with three replications. Pole-type French bean genotypes showed the significant variation for plant morphological traits and grain yield. Genotype LB-31 exhibited significantly the highest pod number (78.0/plant), green pod weight (675.0 g/plant), green pod yield (36.1 t/ha), and dry grain yield (2.4 t/ha). Following LB-31 genotype, genotype Chaumase and LB-39 produced the highest green pod yield (31.3 t/ha and 31.2 t/ha, respectively). The number of clusters per plant, pod number per plant and green pod weight per plant exhibited the significant positive correlation with green pod and dry grain yield. Hence, these traits can be selected to improve the yield potential of pole-type French bean genotypes. Pole type French bean genotypes used in the experiment were well adapted to the study area. Therefore, the high yielding genotypes viz LB-31, Chaumase and LB-39 could be recommended to use as seed source for on-farm production in Mid-Western Nepal.

Development of a genome-wide InDel marker set for allele discrimination between rice (Oryza sativa) and the other seven AA-genome Oryza species

Wild relatives of rice in the genus Oryza (composed of 24 species with 11 different genome types) have been significantly contributing to the varietal improvement of rice (Oryza sativa). More than 4000 accessions of wild rice species are available and they are regarded as a “genetic reservoir” for further rice improvement. DNA markers are essential tools in genetic analysis and breeding. To date, genome-wide marker sets for wild rice species have not been well established and this is one of the major difficulties for the efficient use of wild germplasm. Here, we developed 541 genome-wide InDel markers for the discrimination of alleles between the cultivated species O. sativa and the other seven AA-genome species by positional multiple sequence alignments among five AA-genome species with four rice varieties. The newly developed markers were tested by PCR-agarose gel analysis of 24 accessions from eight AA genome species (three accessions per species) along with two representative cultivars (O. sativa subsp. indica cv. IR24 and subsp. japonica cv. Nipponbare). Marker polymorphism was validated for 475 markers. The number of polymorphic markers between IR24 and each species (three accessions) ranged from 338 (versus O. rufipogon) to 416 (versus O. longistaminata) and the values in comparison with Nipponbare ranged from 179 (versus O. glaberrima) to 323 (versus O. glumaepatula). These marker sets will be useful for genetic studies and use of the AA-genome wild rice species.

Production, varietal improvement programme and seed availability of annual oilseeds in India: Current scenario and future prospects

Oilseeds are important components ofIndian Agriculture. The demand for oilseeds and edible oils would be 61.5 million tonnes and 17.2 million tonnes, respectively, during 2021-22 and the projected supply of oilseeds be only 39.20 million tonnes against the highest ever production of oilseeds in India i.e. 33.42 m t during 2019-20. As the level of self sufficiency is around 40%, there has been a large import of vegetable oils valued at `81,097 crores during 2020-21 to meet the consumption requirement of the country. Therefore, it is imperative to evolve new climate resilient technologies to increase production. Use of high yielding varieties and quality seeds with a contribution of 15%-20% each to the yield, is the first and foremost approach to enhance oilseeds production. The present paper reviews the current scenario of kharif and rabi annual oilseeds, development of varieties, their induction in to the seed chain and seed production during the last decade (2010-11 to 2019-20). Oilseeds area, production and yield showed inconsistent trend during the decade. The highest area (28.05 mha), production (33.42 m t) and yield (1284 kg/ha) were recorded during 2013-14, 2019-20 and 2017-18, respectively. Area under sesame, niger, linseed, sunflower, safflower and castor ubstantially decreased during 2019-20 and consequently the production also decreased as compared to the base year (2010-11). Nevertheless, there was increase in yield/ha of these crops barring soybean. A total of 299 varieties of nine oilseed crops were developed during the last 11 years. This includes 23 bio-fortified varieties having nutritionally superior-edible oil such as high oleic acid in groundnutand safflower, high linoleic acid in linseed, low erucic acid (and concomitant increase in oleic acid) in oil and/or lowglucosinolates in seedmeal in rapeseed-mustard and KITand lipoxygenase free soybean. Seed production chain of oilseeds during 2020-21 consisted of 261 varieties/hybrids comprising 62 of groundnut, 48 of soybean, 64 of rapeseed-mustard, 29 of sesame, 26 of linseed, 9 of niger, 7 of sunflower, 12 of safflower and 4 of castor including 152 varieties released during the last 10 years (up to 2020). There has been a continuous surge in the requirement for seeds of oilseed crops from 2010-11 (57.88 lakh q) until 2018-19 (58.56 lakh q). Seed requirement during 2019-20 was lower (55.61 lakh q) by 3.9% (2.27 lakh q). The highest seed requirement (67.13 lakh q) for seeds was during 2014-15, an increase of about 16.0%. Seed availability during the decade was always higher except for 2014-15 and 2015-16 which recorded 7.7% and 13.6% shortfall, respectively. The seed replacement rate was morethan ideal except for groundnut, castor and sunflower and varietal replacement rate was also high. Bridging the huge yield gap and bringing additional lands in non-traditional areas and/or seasons and utilization of rice fallows are some ofthe options for enhancing oilseeds production. The latter, needs systematic and concerted efforts to identify suitable varieties and develop matching technologies involving time and cost. Efforts should be made, in the first instance, to reduce yield gap to below 20% in the next 3-4 years by facilitating access of farmers to timely availability of various critical inputs including credit, regular and timely technical backstopping and attractive remunerative prices to the crop produce through market interventions. This would lead to gear up additional production of oilseeds up to 9.0 m t in the immediate future.

Thirty years of agronomy research for development in irrigated rice-based cropping systems in the West African Sahel: Achievements and perspectives

Rice (Oryza spp.) is an important food crop and plays an essential role in food security in the Sahel region in West Africa. The Africa Rice Center (AfricaRice) Regional Station for the Sahel was established in 1976 to respond to the demand for increased domestic production through research for development (R4D). This paper aims to review 30 years of rice agronomy R4D in this region and provide perspectives for future research. Rice is mainly grown by smallholders in irrigated systems in the Sahel, where productivity is higher than in other African regions. However, there is still a large gap between potential yield and actual yield obtained by farmers, due to various factors including sub-optimal crop management (e.g. nutrient, weed, water management) and abiotic stresses (e.g. extreme temperatures, salt-affected soils). AfricaRice has developed crop simulation models, integrated crop management practices, water-saving technologies, agronomic interventions alongside salt-tolerant varieties, and decision-support tools for field-specific nutrient management (e.g. “RiceAdvice”). While evaluation of agronomic options is well covered in the literature, there is limited information on scaling and impact in terms of improved smallholder livelihoods. While results from long-term soil fertility trials show that double-cropping rice with appropriate fertilizer application can be sustainable, models that integrate climate change indicate a huge risk of yield reduction due to heat stress, especially in the dry season, unless adaptations such as change in sowing date and varietal improvement are applied. There has been limited research on farming systems beyond plot-level agronomy, and less focus on environmental and social sustainability than economic sustainability (i.e. yield and profit). Further R4D efforts are needed to scale out and scale-up agronomic options for enhancing the productivity and sustainability of irrigated rice-based cropping systems in the Sahel in the context of increasing competition for water, land, and labor under increasingly extreme weather conditions. Digital approaches such as the decision support tool “RiceAdvice” could play an important role in out-scaling of productive, profitable, and sustainable agronomic options.

Analysis of genetic diversity and water-stress tolerance in Tunisian plums [Prunus.spp; Rosacea

Prunus L. (Rosaceae), a genus of over 230 species, exhibits gametophytic self-incompatibility system (GSI). In this study, we explored the patterns of variability in Plum genotypes carrying different reproductive systems, using 36 microsatellite markers (SSRs) and the S-locus. The analysis of genetic diversity showed a rich genetic variability of the studied genotypes. Linkage Disequilibrium decayed rapidly in analyzed plums reaching the significant value (r² = 0.1) at 7.5 cM. Also, we examined the patterns of variability at the end of the sixth linkage group to emphasize the effect of the S-locus on the surrounding region. The genetic diversity in the genomic neighborhood of the S-locus is related to the negative frequency dependent selection (NFDS) which can extend the high polymorphism at the selected locus to closely linked neutral sites. We conducted a drought stress on Tunisian plum to test their response. The analysis of five morphological parameters tested under drought conditions allowed selecting five plum genotypes (one hexploid and four diploid) characterized by their important tolerance to drought stress. These genotypes may be selected as important rootstock for varietal improvement.

Population structure and phylogenetic relationship of Peach [Prunus persica (L.) Batsch] and Nectarine [Prunus persica var. nucipersica (L.) C.K. Schneid.] based on retrotransposon markers

For effective varietal improvement of horticultural crops peach (Prunus persica) and nectarine (Prunus persica var. nucipersica), information about their population structure and genetic relatedness plays an important role. In this study we used retrotransposon-based markers (iPBS) to estimate the genetic diversity and population structure of 48 peach and nectarine genotypes from various distinct geographical regions of Punjab and Khyber Pakhtunkhwa, Pakistan. A total of 461 alleles were identified from PCR amplicons derived from nine iPBS primer pairs with an average of 8.5 alleles/locus. Among all four groups the genotypes collected from Swat and Hunza had the highest and the lowest expected heterozygosity, unbiased expected heterozygosity and Shannon’s information index, respectively. We constructed a Neighbour-Joining dendrogram and performed principal coordinate analysis based on the distance matrices, and both forms of analysis grouped the 48 genotypes into two distinct clusters. The STRUCTURE software distributed the forty-eight genotypes into two main populations (k = 2) indicating a low diversity between genotypes collected from Chakwal, Swat, Mansehra and Hunza.

Application of microsatellite markers for hybrid verification and genetic analysis of oil palm (Elaeis guineensis Jacq.)

The legitimacy of parents and progenies used in crop improvement programmes is vital for any meaningful progress in selection. While acknowledging the shortcomings of controlled pollination in oil palm breeding and commercial seed production, the legitimacy of 20 oil palm progenies from the Nigerian Institute for Oil Palm Research (NIFOR) breeding programme was determined using 16 fluorescently-labeled microsatellite markers. The genotyping of parents and progenies was conducted by capillary electrophoresis using the ABI 3730 DNA Genetic Analyzer (Applied Biosystems, USA). Results revealed a complementary expression of the parents’ alleles in 18 out of the 20 individual progenies screened, confirming their hybridity and genetic identity. The two illegitimate progenies detected could be attributed to pollination and planting errors, respectively. A subset of three sufficiently informative loci (sMg00016, sMg00179 and sMo00102) was identified for routine quality control genotyping. The detection of illegitimate progenies provided ample evidence to substantiate the importance of assessing hybrid fidelity in breeding programmes. Furthermore, the usefulness of microsatellite markers as a reliable technique for routine assessment and unambiguous identification of oil palm crosses was established. The implications of microsatellite- based hybrid identification in oil palm varietal improvement programmes have been adequately discussed.
 Key words: Contamination, Genetic identity, Illegitimacy, NIFOR, Parent-Progeny relationships, seed production

Phenotypic Characters and Expression of Cytokinin oxidase 2 (OsCKX2) Gene in Rice Genotypes with Enhanced Grain Filling Traits

Poor grain filling is still a major problem in rice production. Recent attention in crop varietal improvement is focused on heritable delayed foliar senescence, enhanced root system, and fast-synchronous grain filling pattern. Nine genotypes were characterized for these three enhanced grain-filling traits to determine the role of these traits on grain yield. Based on heritable delayed foliar senescence, NSIC Rc436 and NSIC Rc512 were characterized as Type A, while PSB Rc18 and NSIC Rc514 as Type B. These genotypes had a significantly higher yield than IR64, owing to their high spikelets number. Data suggested a positive correlation between the delayed foliar senescence and grain number. NSIC Rc480, Arabon, Biniding (IR68), NSIC Rc512, Cuevas, and NSIC Rc436 were characterized with phenotypically superior root characters than IR64. A tendency of direct association was observed between the root characters and the percentage of filled grains and 500-grain weight. Only NSIC Rc480 was characterized with a fast-synchronous pattern, and its percentage of filled grains was significantly higher than the other tested genotypes. Integrating these enhanced grain filling traits in the selection criteria may improve poor grain filling in rice, which is a major constraint in improving the rice yield potential. Preliminary work on the expressions of Cytokinin oxidase 2 (OsCKX2), a gene implicated in the regulation of rice grain yield, was likewise conducted. Differences in the OsCKX2 expression was observed, which may entail a positive note on the exploration at the molecular level to identify the possible role of cytokinin in the gene regulation during rice grain filling.

Isolation and Characterization of Fungi strains associated with Mycotoxin Production from Bambara (Vigna subterranea (L) verdc) nuts Recovered in Nigeria

Fungal contamination of food commodities is a global food security challenge that impacts negatively on the health of consumers. Mycotoxins are produced as secondary metabolites by some pathogenic fungi and may contaminate agricultural products while on the field or during harvesting and storage. A field survey was conducted in order to isolate and identify the mycotoxin-producing fungal strains in Bambara nut collected from major markets in eight States in Nigeria including Oyo, Ogun, Lagos, Ekiti, Kwara, Kogi, Abuja, and Nasarawa. Samples per site were pooled, processed and screened for the presence of mycotoxin-producing fungi by culture technique and intergenic spacer sequencing (ITS). Mycotoxin production was determined using thin layer chromatography (TLC) with scanning densitometer. Twenty-four mycotoxin-producing fungal species were isolated from Bambara samples, which were identified as Talaromyces pinophilus, Macrophomina phaseolina (6), Fusarium oxysporum (2), Aspergillus foetidus, Aspergillus flavipes, Rhizopus oryzae (2), Phanerochaete chrysosporium, Aspergillus flavus (2), Aspergillus terreus, Aspergillus awamori, Aspergillus welwitschiae, Rhizopus microsporus, Ceriporia lacerate and Fusarium verticillioides (accession numbers of MN42329- MN4233323) from Bambara nuts. The genera Macrophomina were the most dominant. Some of the identified fungi are noted for the production of mycotoxins and mycotoxins exert toxic effects on animals and humans. The fungi associated with Bambara nut diseases were identified and can be taken as targets in varietal improvement of Bambara nut for resistance to fungal diseases in Nigeria.

Molecular Characterization of Okra Genotypes Through RAPD and SSR Markers

Okra (Abelmoschus esculentus L.) is an important nutritious vegetable. Despite its high economic and industrial value, very little attention has been paid to assess genetic diversity of okra at molecular level. For effective conservation and proper deployment of germplasm, a study on genetic diversity analysis for fiber quality traits of okra germplasm was conducted with Random Amplified Polymorphic DNA (RAPD) and simple sequence repeat (SSR) markers. Random Amplified Polymorphic DNA as well as simple sequence repeat markers were utilized to evaluate the genetic diversity among ten genotypes viz., GAO 5, AOL 12–55, AOL 10–22, AOL 13–73, AOL 13–75, AOL 13–88, AOL 13–90, Parbhanikranti, Pusasawani and wild type. A set of 15 RAPD primers were tested, total of 153 RAPD scorable fragments were produced of which all alleles were observed to be polymorphic. PIC values ranged from 0.77 to 0.92 with an average value of 0.84. The genotypes were broadly divided into two clusters. Cluster II included only wild type genotype. Sub cluster A1 comprised of genotype GAO 5. For SSR all 15 primers showed amplification and produced a total of 31 bands. The genetic distance (GD) among the okra genotypes ranged from 0.18 to 0.60. The highest GD (0.60) was detected between GAO 5 and Wild type, while the lowest GD (0.18) was observed between AOL 13–73 and AOL 13–88. The average observed mean heterozygosity was 0.60 and observed mean percentage of polymorphic loci was 67%. The diversity obtained could be exploited in the program of selection and varietal improvement of okra.

Agromorphological Characterization of Introgression Lines Derived from Wild and Exotic Sorghum Germplasm to Climate Change Challenges

Sorghum (Sorghum bicolor (L.) Moench) is vitally important for food security in semi-arid West Africa. The introgression of wild- and high transpiration efficiency genotypes may contribute genes for abiotic stress tolerance or novel traits. Characterizing the introgressed lines can help researchers in the process of varietal improvement. The objectives of this study are (i) To learn if introgression of wild sorghum (CWR) and high transpiration efficiency (HTE) lines into a very early maturing (photoperiod insensitive) local land-race variety can create useful variation for grain yield in drought-prone Sahelian environments, (ii) To determine if grain yield advantages (and putative drought tolerance traits) obtained from introgression of CWR and HTE germplasm are expressed differently in moderately to highly moisture-limited environments, and (iii) To understand the relationship between putative drought tolerance traits. These populations were developed from crosses between the CSM63E (Jakumbe, a high grains quality variety) and two wild parents (accessions) and five high transpiration efficiency (TE) sorghum accessions. Phenotyping was conducted using an alpha lattice design with three replications in two environments for agronomic traits (grain yield and components), flowering time and physiological traits (stay-green, chlorophyll content and lodging). A total of 669 BC1F5 progenies were developed. Genetic variation for grain yield and putative drought tolerant traits were evaluated. Both populations derived from wild parents exhibited in Cinzana a grain yield (>300 g/m2) greater than CSM63E (245 g/m2). In Bema, more than 75% of the progenies of all populations indicated a chlorophyll content at physiological maturity (>30 SPAD) higher than CSM63E (20 SPAD) chlorophyll content. The estimated broad sense heritability was generally high (≥0.50) for all traits. The results also showed a very significant interaction between genotype and environment for grain yield, flowering time, chlorophyll content, stay green and lodging. There was a strong correlation between stay green and chlorophyll content (0.60) on the one hand and between stay green and lodging (0.48) on the other. This great variability could help improve the grain yield of sorghum for farmers in the Sahelian zone.

Genetic Diversity of Local Rice Accessions Cultivated in Guinea Based on Agro-Morphological Traits and Identification of Sources of Tolerance to Iron Toxicity

In Guinea, traditional rice varieties are the most widely cultivated in rural areas despite their low yield and high susceptibility to iron toxicity. Moreover, the introduction of new improved varieties tolerant to iron toxicity poses a serious threat to the preservation of the genetic resources of these traditional varieties, whose genetic diversity remains poorly known. The present study therefore aims at a better valorisation of these local rice cultivars through the evaluation of their agromorphological diversity and the identification of genotypes potentially tolerant or resistant to iron toxicity. Thus, 90 accessions collected in the regions of Kindia and Macenta and six controls susceptible or resistant to iron toxicity (AZUCENA, BOUAKE 189, CK 73, IR64, NERICAL 19 and AURYLUX 6) were evaluated in three replicate alpha lattice designs in two sites (Seredou and Kilissi) using 16 agromorphological traits. The results showed significant agromorphological variability of the traditional accessions at both sites for all qualitative and most quantitative traits studied. In addition, 30 local cultivars expressed similar or higher grain yields than the resistant or tolerant controls at both sites, of which 12 were found to be stable at both sites. Of the 12 cultivars identified, five were resistant and seven tolerant to iron toxicity. These 12 accessions could be used in the varietal improvement of lowland rice in Guinea Conakry.

Estimation of heterosis for yield and it’s components in chickpea (Cicer arietinum L.)

Chickpea is highly self-pollinated crop and the scope for exploitation of hybrid vigour will depend on the direction and magnitude of heterosis, biological feasibility and the type of gene action involved. Also study of heterosis will have the direct bearing on the breeding methodology to be employed for varietal improvement. The experiment was conducted at Pulses Research Unit, Dr. P.D.K.V. Akola, during rabi season of 2018-19. In this study, four lines were crossed with six male parents by using line x tester design and twenty four hybrids were developed along with the variety JAKI-9218 as standard check have been evaluated in RBD with two replication. The highest mean performance was recorded in PDKV Kanchan x GJG-0814 (27.65g) and significant standard heterosis (15.45% over check JAKI-9218), heterobeltiosis (20.22) and average heterosis (25.68). Another cross Phule Vikram x C-1821 revealed high mean performance for (26.50 g) for seed yield per plant also recoded high magnitude of useful heterosis (10.65 over check JAKI-9218).

Heterosis for seed, oil yield and quality of some different hybrids sunflower

Twenty-one hybrids of sunflower were produced by crossing 7 introduced cytoplasmic male sterile lines (CMS-lines) with 3 restorer lines (RF-lines) using line × tester mating design. The twenty-one hybrids, three restorers, seven maintainer lines (B-lines) were evaluated. The experiment was conducted in a randomized complete block design of three replications. Mean squares due to genotypes, parents (P), crosses (C), lines (L), testers (T), P vs. C, for stearic acid and line × tester for palmitic acid. The inbred lines and their F1 hybrids differed significantly in their mean values of the traits under study. The variances due to specific combining ability (SCA) were higher than general combining ability (GCA) variances for all the studied traits, showing non-additive type of gene action controlling the traits. Non-additive type of gene action can be utilized for varietal improvement through heterosis breeding. Heterosis values for seed yield plant−1 were positive and highly significant relative to both the parental mean (17.68–72.38%) and the better parent (−2.86–56.842%). Significantly and negative heterosis was recorded in the case of linoleic acid relative to the parental mean (−81.24 to −38.02%) and better parent (−66.24–22.87%). With oleic acid, the heterotic effect ranged from −14.18 to 39.59% (parental mean) and from −15.06 to 38.72% (better parent). Therefore, these results are valuable for the improvement of quantitative as well as qualitative traits in sunflower breeding material to fulfill the edible oil requirements.

Local Taxonomy and Diversity of Chadian Sorghum [<i>Sorghum bicolor</i> (L.) Moench] Accessions

The integration of local plant genetic resources into the breeding program is an asset for research. The objective of this study is to assess the diversity and analyze the management practices of cultivated sorghum. A questionnaire following a participatory approach was submitted to 675 producers in 45 villages. The cultivars collected were characterized using 9 qualitative descriptors. In total, 151 accessions and 191 names were inventoried. On average, 25.17 accessions per department and 3.36 accessions per village. Local taxonomy is based on many criteria expressed in different local languages. The most common method of naming is that to the word sorghum is added either the color of the grain, the precocity, or any element deemed relevant by the farmers. Significant variability in grain and panicle traits was observed within the collection, except the color of the endosperm. The rate of diversity loss is 11.52% and red grain sorghums are the most threatened with extinction. Five accessions groups are differentiated by the presence or absence of awns, the color of glumes, and amount of grain covered by glumes, grain plumpness, and form. Based on productivity, precocity, plant size, seed shape, and color, the farmers identified seven promising accessions. This potential will be preserved and developed in the sorghum varietal improvement program in Chad.

Molecular Diversity Analysis in Cotton (Gossypium hirsutum L.) Using RAPD Markers

Cotton (Gossypium hirsutum L) is considered as major textile fiber around the world. This research aimed to analyze the molecular diversity among 9 cotton genotypes collected from Cotton Development Board, Bangladesh using the 7 Random Amplified Polymorphic DNA (RAPD) markers. Some total of 18 DNA bands were obtained and among them, 13 were polymorphic bands. The range of DNA amplification varied from 180 to 800 bp. The percentage of polymorphism was about 50.71. Genetic diversity ranged from 0.22 to 0.44 with an average value of 0.34. Nei’s genetic distance ranging from 0.1667 to 0.6667 and most importantly PIC value ranged from 0.18 to 0.35 with an average value of 0.27. The PIC value indicated that most of the studied cotton genotypes were moderately diversified and homogenous as well as no heterozygosity found. A dendrogram indicating the relative genetic similarity of the Bangladeshi cotton genotypes was constructed which followed in two major clusters (A and B) among the studied material. The Cotton Development Board (CDB), Bangladesh committed to working on cotton improvement and this investigation will be helpful for the selection of diversified genotypes in varietal improvement in cotton. The output of this research will be a baseline for future molecular research work on cotton genotypes in Bangladesh.

Genetic Variability, Heritability, and Clustering Pattern Exploration of Bambara Groundnut (Vigna subterranea L. Verdc) Accessions for the Perfection of Yield and Yield-Related Traits.

Bambara groundnut (Vigna subterranea L. Verdc.) is considered an emerging crop for the future and known as a crop for the new millennium. The core intention of this research work was to estimate the variation of landraces of Bambara groundnut considering their 14 qualitative and 27 numerical traits, to discover the best genotype fitted in Malaysia. The findings of the ANOVA observed a highly significant variation (p ≤ 0.01) for all the traits evaluated. There was a substantial variation (7.27 to 41.21%) coefficient value, and 14 out of the 27 numerical traits noted coefficient of variation (CV) ≥ 20%. Yield (kg/ha) disclosed positively strong to perfect high significant correlation (r = 0.75 to 1.00; p ≤ 0.001) with traits like fresh pod weight, dry pod weight, and dry seed weight. The topmost PCV and GCV values were estimated for biomass dry (41.09%) and fresh (40.53%) weight with high heritability (Hb) and genetic advance (GA) Hb = 95.19%, GA = 80.57% and Hb = 98.52%, GA = 82.86%, respectively. The topmost heritability was recorded for fresh pod weight (99.89%) followed by yield (99.75%) with genetic advance 67.95% and 62.03%, respectively. The traits with Hb ≥ 60% and GA ≥ 20% suggested the least influenced by the environment as well as governed by the additive genes and direct selection for improvement of such traits can be beneficial. To estimate the genetic variability among accessions, the valuation of variance components, coefficients of variation, heritability, and genetic advance were calculated. To authenticate the genetic inequality, an unweighted pair group produced with arithmetic mean (UPGMA) and principal component analysis was executed based on their measurable traits that could be a steadfast method for judging the degree of diversity. Based on the UPGMA cluster analysis, constructed five distinct clusters and 44 accessions from clusters II and IV consider an elite type of genotypes that produce more than one ton yield per hectare land with desirable traits. This study exposed an extensive disparity among the landraces and the evidence on genetic relatives will be imperative in using the existing germplasm for Bambara groundnut varietal improvement. Moreover, this finding will be beneficial for breeders to choose the desirable numerical traits of V. subterranea in their future breeding program.

EVALUATION OF SALT AND HEAVY METAL STRESS FOR SEEDLING TRAITS IN WHEAT

Wheat (Triticum aestivum L.) is an important cereal crop of the world. It is one of the staple foods for major portion of world population. There are various biotic and abiotic factors responsible for low production of wheat in our country. Among these factors, soil salinity is major problem playing an important role in soil degradation, thus consequently reducing wheat production and quality. This study was conducted to evaluate the effect of various salinity and heavy metal levels against three wheat cultivars fir salinity resistance. Three different varieties of wheat were screened against the salinity under controlled conditions in the laboratory of tissue culture, University of Lahore. Seeds of three wheat varieties (Anaj-2006, Faisalabad-2008 and Inqalab-91) were sown in seedling trays. NaCl and CuSO4 were applied as salinity and heavy metal treatment upon wheat cultivars. In order to evaluate, hazardous effects of salinity and heavy metal on wheat certain growth parameters were observed i.e. leaf length and width, leaf area, stem and root length, fresh and dry weight of leaf, stem and root, root shoot length ratio and photometry of leaf, stem and root was measured. Results depicts salinity and heavy metal application has negative correlation with growth parameters of wheat particularly combine application of NaCl and CuSo4 have led to impose major detrimental effects on wheat cultivars. Regarding varietal comparison, “Anaj-2006” proved to be comparatively better in context of less salt’s residual accumulation in leaf, stem and roots along with lower root to shoot length ratio thus exhibiting a strong genetic potential to keep surviving and maintain healthy growth. However, it was concluded that salinity and heavy metal have adversely affected growth and yield potential of “Faisalabad-2008”. So conclusively, there is dare need to screen out indigenous and exotic wheat germplasm available throughout the country for finding some suitable genetic resources having moderate to high resistance levels against salinity and heavy metal which can be further used for breeding purpose in varietal improvement program.