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1.
Benjamin Annor Baffour Badu-Apraku Daniel Nyadanu Richard Akromah Morakinyo A. B. Fakorede 《Plant Breeding》2020,139(4):708-716
Identification of heterotic groups and efficient testers, which are important prerequisites for the development of outstanding hybrids, has been a major challenge to its success, especially for early and extra-early germplasm. This study was carried out to (a) identify the most efficient heterotic grouping method for classifying a set of inbred lines and (b) determine the efficiency of testers in classifying inbred lines into heterotic groups. A total of 205 hybrids obtained by crossing 41 inbred lines with five standard testers were evaluated together with five hybrid checks under drought, low soil nitrogen (N), Striga-infested and optimal environments in Nigeria between 2014 and 2016. The heterotic group's specific and general combining ability (HSGCA) method was more effective in classifying the inbred lines into heterotic groups. Testers TZEI 17 and TZEI 23 were the most efficient across environments and could be invaluable for classifying other lines into heterotic groups and assessing combining ability of maize inbreds. In addition, these testers and heterotic groups represent an invaluable resource for development of outstanding hybrids in sub-Saharan Africa (SSA). 相似文献
2.
以不同类群的18个玉米自交系为母本,6个标准测验种为父本,利用NC-II设计,组配108个杂交组合,对亲本自交系氮效率相关性状进行统计分析,并对杂交组合的产量及氮效率相关性状进行配合力分析。结果表明,吐丝期叶绿素相对含量在2个施氮处理下均与氮效率呈极显著正相关(r = 0.553, 0.639),可作为评价亲本自交系氮效率高低的指标;从氮效率2个构成方面来看,不施氮处理下氮利用效率起主要作用,而施氮处理下氮吸收效率起主要作用。亲本氮效率配合力分析表明,在氮高效品种选育中,应保证亲本至少有一个是氮效率一般配合力(GCA)较高的自交系,并选择由其组配的氮效率特殊配合力(SCA)高的组合;双亲的配合力氮效率总体效应(TCA)决定着组合F1代的产量及氮效率,TCA可作为选育氮高效杂交组合的理论依据。母本自交系BL12、BL48分别在施纯氮225 kg hm-2 (N225)和450 kg hm-2 (N450)处理下,具有较高的GCA效应,是较好的氮高效育种材料,其杂交组合BL12×178、BL48×掖478分别在N225,N450处理下表现较优,是优良的氮高效杂交组合。 相似文献
3.
Drought and low soil fertility are considered the most important abiotic stresses limiting maize production in sub-Saharan
Africa. Knowledge of the combining ability and diversity of inbred lines with tolerance to the two stresses and for those
used as testers would be beneficial in setting breeding strategies for stress and nonstress environments. We used 15 tropical
maize inbred lines to (i) evaluate the combining ability for grain yield (GY), (ii) assess the genetic diversity of this set
of inbred lines using RFLP, SSR, and AFLP markers, (iii) estimate heterosis and assess the relationship between F1 hybrid performance, genetic diversity and heterosis, and (iv) assess genotype × environment interaction of inbred lines and
their hybrids. The F1 diallel hybrids and parental inbreds were evaluated under drought stress, low N stress, and well-watered conditions at six
locations in three countries. General combining ability (GCA) effects were highly significant (P < 0.01) for GY across stresses and well-watered environments. Inbred lines CML258, CML339, CML341, and CML343 had the best
GCA effects for GY across environments. Additive genetic effects were more important for GY under drought stress and well-watered
conditions but not under low N stress, suggesting different gene action in control of GY. Clustering based on genetic distance
(GD) calculated using combined marker data grouped lines according to pedigree. Positive correlation was found between midparent
heterosis (MPH) and specific combining ability (SCA), GD and GY. Hybrid breeding program targeting stress environments would
benefit from the accumulation of favorable alleles for drought tolerance in both parental lines. 相似文献
4.
Test‐crosses for estimating combining ability in potato although useful are difficult to make being labour intensive and time consuming, and due to the problem of sterility. The objective of the present study was to test methods for estimating general combining ability (GCA) of parents based on fewer matings. The GCA of 12 females estimated based on matings with specific single testers (top‐cross) and three types of bulk pollen (poly‐cross) were compared with those estimated by 72 (12 × 6) test‐crosses, using common testers in three types of matings. The study was conducted for 2 years at each of the two locations representing short‐days subtropical conditions in plains and long‐days temperate conditions in hills of India. Analysis of variance of test‐crosses showed that both general and specific combining ability effects were important for tuber yield, late blight resistance as well as general impression, the characters studied. Correlation coefficients among three types of matings showed that bulk pollen matings had poor effectiveness in predicting the GCA of the females, whereas matings with selected individual testers resulted in GCA estimates similar to those based on six testers. Thus use of top‐cross involving selected tester could substantially reduce the number of matings required for estimating the GCA. Among the six testers used, the tester CFK69.1 could estimate the GCA of the females with reasonably high accuracy both for tuber yield and general impression, and ‘Tobique’ for reaction to late blight. 相似文献
5.
Maize (Zea mays L.) is an important staple food crop in West and Central Africa (WCA). However, its production is constrained by drought. Knowledge and understanding of the genetics of hybrid performance under drought is invaluable in designing breeding strategies for improving maize yield. One hundred and fifty hybrids obtained by crossing 30 inbreds in sets using the North Carolina Design II plus six checks were evaluated under drought and well‐watered conditions for 2 years at three locations in Nigeria. The objectives of the studies were to (i) determine the mode of gene action controlling grain yield and other important agronomic traits of selected early inbred lines, (ii) examine the relationship between per se performance of inbreds and their hybrids and (iii) identify appropriate testers for maize breeding programmes in WCA. General combining ability (GCA) and specific combining ability (SCA) mean squares were significant (P < 0.01) for grain yield and other traits under the research environments. The GCA accounted for 64.5 % and 62.3 % of the total variation for grain yield under drought and well‐watered conditions, indicating that additive gene action largely controlled the inheritance of grain yield of the hybrids. Narrow‐sense heritability was 67 % for grain yield under drought and 49 % under well‐watered conditions. The correlations between traits of early‐maturing parental lines and their hybrids were significant (P < 0.01) under drought, well‐watered and across environments. Mid‐parent and better‐parent heterosis for grain yield were 45.3 % and 18.4 % under drought stress and 111.9 % and 102.6 % under well‐watered conditions. Inbreds TZEI 31, TZEI 17, TZEI 129 and TZEI 157 were identified as the best testers. Drought‐tolerant hybrids with superior performance under stress and non‐stress conditions could be obtained through the accumulation of favourable alleles for drought tolerance in both parental lines. 相似文献
6.
The relative importance of general and specific combining ability (GCA and SCA, respectively), amount and causes of heterosis and inferences for breeding strategies were assessed for trypsin inhibitors activity (TIA) and seed protein content (SPC) in Vicia faba test-crosses. Four lines with low (‘Bond’) and high (‘H2OS’, ‘98/Tunesien’ and ‘Canner Express’) TIA, and two testers (‘Rowena’ and ‘Felicia’) with low TIA were used to produce test-crosses. GCA accounted for 89% and 57% of the test-cross sums of squares for SPC and TIA, respectively; SCA accounted for 48% and 34%, and differences between reciprocals for 6% and 9%. Specific heterosis was large only in low TIA × low TIA test-crosses and tended towards an increased TIA. Epistatic interaction explained the observed specific heterosis for high TIA. Breeding faba bean hybrids for high SPC and low TIA is not convenient because non-additive gene actions exert minimal effects on SPC or are in the undesired direction for TIA. Selecting inbred lines which combine low TIA, good SPC and satisfactory grain yield is more promising] Rowena and Rowena × Bond are adequate as base materials. 相似文献
7.
Heterotic patterns in rapeseed (Brassica napus L.): II. Crosses between European winter and Chinese semi-winter lines 总被引：1，自引：0，他引：1
Chinese semi-winter rapeseed is genetically diverse from European winter rapeseed. Our objectives were (1) to evaluate the potential of semi-winter rapeseed for winter rapeseed hybrid breeding, (2) to assess the relative importance of general combining ability (GCA) vs. specific combining ability (SCA) among combinations between Chinese semi-winter and European winter rapeseed, and (3) to compare the strategies to predict heterosis based on parental genetic distance (GD) estimated from AFLP marker data and GCA for hybrid performance. Four winter male sterile lines from Germany as testers were crossed with 14 Chinese semi-winter rapeseed lines to develop 56 hybrids, which were evaluated together with their parents and commercial hybrids for seed yield, oil content and protein content under three environments in Germany. The Chinese parental lines were not adapted to local environmental conditions as demonstrated by lacking winter hardiness and poor seed yields per se . However, the hybrids between the Chinese parents and the adapted winter rapeseed lines exhibited high heterosis for seed yield. About 20% of the hybrids were significantly superior to the respective hybrid control under three environments. Additive gene effects mainly contributed to hybrid performance since the variance components of GCA were higher as compared with SCA. The correlation between parental GD and hybrid performance was found to be low whereas the correlation between GCA and hybrid performance was high and significant, with correlation coefficients of 0.95 for seed yield, 0.87 for oil content, and 0.91 for protein content, indicating that GCA can predict hybrid performance. These results demonstrate that Chinese semi-winter rapeseed germplasm has a great potential to increase seed yield in winter rapeseed hybrid breeding programmes in Europe. 相似文献
8.
Xiaogang Liu Xiaojiao Hu Kun Li Zhifang Liu Yujin Wu Guang Feng Changling Huang Hongwu Wang 《Breeding Science》2021,71(2):217
Maize is the most important staple crop worldwide. Many of its agronomic traits present with a high level of heterosis. Combining ability was proposed to exploit the rule of heterosis, and general combining ability (GCA) is a crucial measure of parental performance. In this study, a recombinant inbred line population was used to construct testcross populations by crossing with four testers based on North Carolina design II. Six yield-relevant traits were investigated as phenotypic data. GCA effects were estimated for three scenarios based on the heterotic group and the number of tester lines. These estimates were then used to identify quantitative trait loci (QTL) and dissect genetic basis of GCA. A higher heritability of GCA was obtained for each trait. Thus, testing in early generation of breeding may effectively select candidate lines with relatively superior GCA performance. The GCA QTL detected in each scenario was slightly different according to the linkage mapping. Most of the GCA-relevant loci were simultaneously detected in all three datasets. Therefore, the genetic basis of GCA was nearly constant although discrepant inbred lines were appointed as testers. In addition, favorable alleles corresponding to GCA could be pyramided via marker-assisted selection and made available for maize hybrid breeding. 相似文献
9.
为了充分利用新近合成的优质、抗逆甜玉米群体,同时加速育种进程。试验采用不完全双列杂交设计,以2个自育超甜玉米骨干系作测验种,与63个穗行的75个单株杂交,配制组合150个,通过杂交组合鉴定试验、株系的食用品质及抗性等的鉴定评价,对群体配合力及遗传潜势进行了分析,结果发现在75个被测株中,36个株系的单株产量一般配合力为正,而通过对其产量相关性状、商品性及农艺性状一般配合力分析也发现,其GCA表现较好的株系比例接近或超过50%。结合株系自身表现,筛选获得9个苗头株系;同时根据杂交组合鉴定结果,获得8个苗头组合。综合群体内株系的配合力及群体自身表现,初步认为该群体优良基因频率较高,遗传变异较为丰富,具有较大利用潜力。 相似文献
10.
Heterosis and combining ability studies were conducted on selected chickpea genotypes in order to (1) acquire an understanding
of the predominant type of gene action governing biomass (BY) and harvest index (HI), (2) estimate the magnitude of heterosis,
(3) estimate combining ability effects and (4) assess correlations between per se performance and general combining ability
(GCA) of the parents under a drought-prone, rainfed short-duration environment (SDE) where BY is considered to be an important
trait for enhancing chickpea productivity. The experimental material comprised 30 F1s obtained by crossing ten adapted genotypes as females to three testers as males in a line × tester design. The GCA variances
were significant and of a high magnitude, while specific combining ability (SCA) variances were non-significant, indicating
the predominant role of additive gene action on BY and the HI. A large number of crosses showed positive mid-parent heterosis
(MPH) and better-parent heterosis (BPH). The average MPH and BPH for BY was 22.36 and 12.65, respectively, and the average
MPH and BPH for the HI was 2.22 and −0.92, respectively. The higher magnitude of the MPH and BPH recorded for BY indicated
that the scope for increasing the HI in chickpea in a drought-prone, SDE is limited and that further increases in productivity
have to come mainly through enhanced BY. The majority of the heterotic crosses involved poor × good combiners. This study
demonstrates that in order to achieve greater progress in improving BY and the HI in chickpea, the selection of parents should
be based on per se performance as well as combining ability and heterosis. 相似文献
11.
Sorghum head bug, Calocoris angustatus Lethiery is one of the most important pests of grain sorghum in India. Head bug damage increases the severity of grain molds,
which renders the grain unfit for human consumption. Therefore, we studied the gene action for resistance to head bugs and
grain molds in a diverse array of male-sterile lines and testers in a line × tester mating design under natural infestation.
Mean squares for parents, parents vs crosses, lines, testers, and lines × testers were significant for head bug damage and
grain mold severity. General combining ability (GCA) effects were significant and negative for ICSA 88019 for head bug damage,
and ICSA 88019 and ICSA 88020 for grain molds (except for ICSA 88020 in 1993). General combining ability effects were positive
for ICSA 42 and 296 A. GCA effects of lines and testers for head bug damage and grain mold severity were in the same direction
(+ve or −ve). Head bug damage in the grain was significantly correlated with grain mold severity. Testers IS 8891, IS 15107,
and TAM 2566 (with colored grain and less susceptibility to molds) produced mold-resistant hybrids in combination with all
the male-sterile lines, while the reverse was true in the case of Swarna and ICSV 112. Resistance to head bugs showed dominance
to partial dominance type of gene action, while in the case of grain molds, it showed dominance to over dominance. Resistance
to these pests is governed by both additive and nonadditive types of gene action. The implications of these results are discussed
in relation to need for crop improvement in sorghum.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
12.
Five inbred lines, 10 single cross maize (Zea mays L.) hybrids and two standard cultivars as check were used to study the combining abilities and heterosis under three environmental
conditions. Random amplified polymorphic DNAs (RAPDs) markers were used to study the genetic diversity (GD) and further to
analyze relationship of RAPDs based GD with combining ability and heterosis in short duration maize. Spearman’s rank correlation
coefficients and linear regressions were analyzed to identify the most important factor determining heterosis and per se performance
of the hybrids. Variances due to general combining ability (GCA), specific combining ability (SCA) and their interactions
with environment were found to be significant. Twenty random primers generated 179 RAPD fragments. Of these, 102 RAPD fragments
were polymorphic. GD was determined using Jaccard’s similarity coefficient, and a dendogram was constructed by UPGMA cluster
analysis. The RAPDs based GD exhibited non-significant negative or positive association, non-significant linear regression
along with very low coefficient of determination (R
2) with SCA, high and mid parent heterosis (HP and MP) and per se performance of the hybrids. Significant positive correlations
and regressions along with high coefficients of determination were recorded for SCA with HP, MP and per se performance of
the hybrids. The HP and MP also established significant positive association and linear regression along with high coefficient
of determination with per se performance of hybrids whereas the parental mean did not establish any significant correlations
with the GD, HPH, MPH and grain yield of F1s. The present investigation, therefore, did not find any role of RAPDs based GD in determining hybrid heterosis and hybrid
performance in short duration sub-tropical maize. The SCA, however, has emerged as the most important factor in determination
of heterosis as well as per se performance of the hybrids in short duration maize. 相似文献
13.
Seventy nine genotypes of tomato (15 lines, four testers and their 60 F1 hybrids produced in line × tester fashion) were evaluated under normal (E1) and late planting (E2) conditions in the Department of Vegetable Crops, Punjab Agricultural University, Ludhiana, India, to determine the nature
of gene action controlling yield, quality and shelf life characteristics and to identify a few good combiner genotypes which
may be used in further breeding programmes to extend the fruit availability period of tomato in North Indian plains. The lines
were significantly different from testers for most of the characters thereby justifying the choice of testers. Additive gene
action was predominant for days to ripening, total yield per plant, marketable yield per plant, number of fruits per plant,
average fruit weight, fruit shape index and lycopene in both the environments, whereas non-additive genetic variance predominated
in controlling firmness index, number of locules, pericarp thickness, alcohol insoluble solids (AIS), dry matter, total soluble
solids (TSS), titratable acidity, TSS:Acid ratio, pH, ascorbic acid and shelf life, under both normal and late planting conditions.
The best general combining ability (gca) effects, among females, in respect of yield per plant were shown by Spectrum in E1 and by LT-42 in E2. Among the testers, the best gca values in both the environments were possessed by nor-RM-1 for total yield per plant, marketable yield per plant, number of fruits per plant, dry matter and TSS; by rin-RM-2 for firmness index, pericarp thickness and alcohol insoluble solids; by alc-IIHR-2050 for average fruit weight, number of locules and shelf life and by alc-IIHR-2052 for lycopene. The gca of ripening mutants had a nice consonance with their per se performance for most of the characters
indicating that additive gene action was operative in these mutants for majority of the traits. 相似文献
14.
Development of top cross varieties with downy mildew (DM) resistance is one approach to enhance maize productivity in tropical lowland environments. The objective of this study was to determine heterotic orientation of 18 advanced maize inbred lines towards popular open pollinated synthetic populations ZM523 and Suwan-1 under the prevalence of DM. The 36 top crosses, four hybrid check varieties and two testers, ZM523 (Z) and Suwan-1 (S) were evaluated in a 6 × 7 α-lattice design with two replications across three environments. General combining ability effects were significant (P ≤ 0.05) for DM resistance and grain yield, suggesting that genes with additive effects were important in controlling the traits. Specific combining ability (SCA) effects were not significant for DM suggesting small influence of DM resistance by the genes with non-additive effects; but SCA effects were significant for grain yield, indicating that non-additive gene effects played a significant role in governing the grain yield. Based on the SCA data, ten lines were grouped with Suwan-1 and eight lines with ZM523. Using the heterosis data, the lines were fitted into three groups that were designated as S, Z and SZ orientation. The lines ML2, ML30 and ML42, which displayed positive heterosis with both testers for grain yield, were allocated to the SZ-group. The lines ML8, ML10, ML25, ML45, and ML48 exhibited positive heterosis with Suwan-1 and were therefore, classified in the Z-group, and line ML19 that showed positive heterosis with ZM523 was fitted in the S-group. The remaining eight lines did not show any significant and positive heterosis with both testers hence they could not be classified based on heterosis data, suggesting that hybrid breeding efficiency could be improved by expanding the number of testers. Line ML42 displayed the highest level of heterosis with both Suwan-1 (32 %) and ZM523 (29 %) and outperformed all the standard check varieties qualifying it as a potential candidate for further testing. Generally, there was consistency of heterotic grouping of the lines using SCA and heterosis data. 相似文献
15.
The European com borer (ECB) Ostrinia nubilalis H. is a major pest in World maize Zea mays L. production. Objectives of this study were to (1) investigate the genotypic variance and covariance in testcrosses of European flint and dent inbreds for ECB resistance and agronomic traits, and (2) estimate the correlation between line per se and testcross performance for ECB resistance traits. A total of 16 flint and 24 dent inbreds and their testcrosses with two testers from the opposite germplasm pool were evaluated in four and three German environments, respectively. Using artificial infestation with ECB larvae, resistance was assessed by damage rating of stalks, tunnel length in dissected stalks, and relative yield of infested plots compared with protected plots. Yield losses due to ECB damage in testcross hybrids amounted to 40%. Significant genotypic variances between flint and dent lines and high heritabilities were found for damage rating of stalks for both line per se and testcross performance. Heritabilities were low or intermediate for tunnel length and relative grain yield. Correlations between line per se and testcross performance were tight for the damage rating of stalks and moderate for tunnel length and relative yield in both flint and dent germplasm. For damage rating of stalks, per se performance of lines tested in a few environments can be used to predict their testcross performance. In contrast, assessment of testcross performance for tunnel length and relative yield requires evaluating testcrosses with several testers in multi-environment trials. 相似文献
16.
The importance of hybrid rye (Secale cereale L.) breeding has steadily increased over the last decades. This paper presents results of model calculations aiming to optimize the number of candidates, testers to assess combining ability and test locations at each selection stage of a standard scheme of seed‐parent line development. Two variants of the scheme differing in the number of stages and the cycle length are investigated. Optimization criterion is the expected selection gain per year under the restriction of a fixed budget. Prediction of selection gain rests on quantitative–genetic and economic parameters estimated from breeders’ data. Optimization covers different genetical and economical situations. Results show that the optimum number of testers to assess combining ability depends on the relative amount of dominance variance. The efficiency of a breeding scheme strongly increases with decreasing cycle length. A larger budget should mainly be used to increase the number of candidates at all selection stages. Recommendations for practical breeding schemes are given. We conclude that model calculations are a valuable tool for the optimization of breeding schemes. 相似文献
17.
17个玉米地方种质选系的育种潜势分析 总被引：5，自引：2，他引：3
以西南地区生产上常用的11个玉米骨干自交系为测验种,采用不完全双列杂交设计,测定17个玉米地方种质新选自交系主要性状的配合力和杂种优势,并对杂优类群、性状遗传参数进行分析。结果表明,单株产量GCA表现突出,且构成产量因子性状GCA表现也较好的新选系有P1-1、P1-16和P1-14;SCA值高、杂种优势强的组合是P1-10×P2-4,四平头群×Lancaster群在川南地区可产生较强的杂种优势;在穗行数、行粒数等4个性状中,亲本的基因加性效应对F1性状形成起主导作用,可早代进行选择,而百粒生、单株产量等5个性状的遗传变异主要来自于基因非加性效应,宜晚代进行选择。 相似文献
18.
Low soil nitrogen (Low N), Striga hermonthica and recurrent drought are major constraints to maize production and productivity in sub-Saharan Africa (SSA). Only a few extra-early maturing hybrids with combined tolerance to drought, Striga and low N have been commercialized in SSA. The objectives of the study were to determine the general combining ability (GCA) and specific combining ability (SCA) effects of grain yield and other traits, classify the inbreds into heterotic groups using the SCA effects of grain yield, and the heterotic group’s SCA and GCA of grain yield (HSGCA) methods, and examine the performance of hybrids under contrasting environments. Sixty-three extra-early white maize inbred lines containing genes from Zea diploperennis were crossed to four elite testers to obtain 252 single-cross hybrids and evaluated together with four checks at four locations for 2 years under drought, Striga-infested, low N and optimal environments in Nigeria. The GCA and SCA effects were significant (P ≤ 0.01) with preponderance of GCA over SCA effects for all measured traits indicating that additive genetic effects were predominant in the lines under all the contrasting environments. The HSGCA was more efficient than the SCA method in the classification of the inbreds into heterotic groups. The hybrids TZdEEI 74 × TZEEI 13 and TZdEEI 74 × TZEEI 29 were high yielding and most stable across research environments. These hybrids should be further evaluated in on-farm trials to confirm the consistency of performance for commercialization in SSA. 相似文献
19.
Fusarium wilt is the main pigeonpea production constraint in Malawi. The purpose of the study was to understand the nature and mechanism of inheritance of F. wilt resistance, yield and secondary traits in pigeonpea. 48 crosses were generated in a 12 lines × 4 testers mating scheme. Some F1 plants were selfed for segregation analysis for inheritance pattern of resistance, while others were evaluated for resistance, yield and secondary traits. There were significant variations among F1 plants for F. wilt, days to 50 % flowering, seed/pod, and number of secondary branches. Specific combining ability (SCA) effects were predominant for F. wilt, days to 50 % flowering and number of secondary branches. The general combining ability (GCA) effects, mainly due to maternal genotypes, were preponderant for yield and other secondary traits. The significance of GCA and SCA effects suggested that variations were due to additive gene action in both the testers and parental lines arising from their interactions, and the dominance effects due to interactions of the parental lines. The χ2 analysis suggested dominant patterns of inheritance for wilt in most of the F2 populations. The segregation ratios of 3:1, 15:1, and 9:7 suggested the involvement of single or two independent/complementary dominant genes in the test donors. Involvement of a few genes governing wilt resistance suggested the ease of breeding for this trait. Pedigree breeding method would be recommended for incorporating various traits in pigeonpea. 相似文献
20.
Summary An investigation was made to exploit an innovative tool viz., thermosensitive genic male sterile (TGMS) system in twoline inter-subspecies rice hybrids using 132 hybrids involving four TGMS lines viz., TS15, TS16, TS18 and TS29 and thirty three testers viz., 17 indicas, 7 japonicas and 9 javanicas by line × tester method at Paddy Breeding Station, Tamil Nadu Agricultural University, India. Pre-ponderence of non-additive gene action for yield and yield attributing traits was observed by analysing combining ability. TGMS lines TS18, TS29 and the testers CB96073, CB96026, CB94247, TNAU 94241 (indicas), Gohykumangoku (japonica), Dular, PRR16 (javanicas) were good general combiners. The hybrids TS29 × TNAU 94241 (indica/indica), TS 18 × Yamadanishiki (indica/japonica) and TS29 × Dular, TS29 × PRR16 (indica/javanica) were promising for heterosis breeding programme. The japonica tester Gohykumangoku and javanica testers Dular and CPSL0-17 exhibited strong heterosis for spikelet fertility when crossed with TGMS lines TS 16, TS 18, TS 29 indicated that these lines may possess wide compatible gene (WCG) for spikelet fertility. Based on mean performance, standard heterosis and sca for yield and yield traits, the inter – subspecies hybrids viz., TS29 × TNAU 94241, TS18 × TNAU 94241, TS29 × CB96073, TS29 × CB94247, TS29 × CB96026 (indica/indica) TS18 × Yamadanishiki, TS29 × Gohykumangoku (indica/japonica), TS29 × Dular, TS29 × PRR16 (indica/javanica) exhibited high heterosis over check hybrid CORH2 and the above hybrids can be exploited commercially. The present investigation revealed that the TGMS system may utilized as an innovative tool for developing inter subspecies two line hybrids with strong heterosis in rice. 相似文献