Extent Of Heterosis For Yield Research Articles

Heterosis for yield and yield attributing traits in tomato (Solanum lycopersicum L.)

Six diverse lines of tomato were crossed with four testers in line x tester (L×T) cross design to investigate the extent of heterosis for yield and its contributing traits in tomato. The present investigation was carried out under AICRP on Vegetable Crops at Horticultural Research cum Instructional Farm, Department of Vegetable Science, IGKV, Raipur (C.G.) during rabi 2017-18. A high degree of heterosis was observed for most of the characters under investigation. High per se performance with remarkable heterosis were expressed by PR x 14/TLCV-3, KA x 15/TLCV-2, H-86 x 14/ TLCV-3, KA x 14/TLCV-3 and H-24 x 14/TLCV-1 for higher fruit yield, however, a high degree of heterosis for other traits in desired direction was also observed.

Heterosis for yield and its related traits in Okra (Abelmoschus esculentus L. Moench)

Eight parental lines of okra and their 28 F 1 hybrids obtained from half diallel were studied to investigate the extent of heterosis for yield and yield attributing characters. The magnitude of heterosis varied from cross to cross for all the characters studied. Maximum positive heterosis for fruit yild per plant over better parent and standard check (JOH 2) was observed to be 62.12 and 44.11 per cent, respectively. The cause of heterosis may be due to its component traits, mainly, days to first flowering, nodes per plant, length of internode, fruit weight and fruits per plant. The best performing hybrid AOL 09-25 x AOL 09-26 which recorded 44.11 per cent heterosis for yield over standard check may be exploited for commercial cultivation.

Exploiting Yield Potential in Cucumber (<i>Cucumis sativus</i> L.) through Heterosis Breeding

Eight genetically divergent parental lines of cucumber were crossed in a diallel pattern to investigate general, specific combining ability and extent of heterosis for yield and its attributing traits. The combining ability analysis revealed that both gca and sca variance were significant for all the characters except equatorial diameter of fruit. Non-additive gene action played a major role in controlling the characters like days taken to first fruit harvest, number of fruits per vine, average fruit weight, diameter of fruit, and average fruit yield. On the basis of gca parent ACC-8 for diameter of fruit and average fruit yield, ACC-2 for days to first fruit harvest and number of fruits per vine, and ACC-4 for average fruit weight were found to be the best general combiner. Cross combinations ACC-2×ACC-6 for days taken to first fruit harvest; ACC-4×ACC-7 for number of fruits per vine; ACC-3×ACC-8 for average fruit weight; ACC-3×ACC-4 for diameter of fruit; ACC-1×ACC-4 for average fruit yield manifested highest sca effects. Cross combination of ACC-1 X ACC-4 and ACC-2 x ACC-6 showed 39.25 and 32.23 heterosis for average fruit yield over standard check, respectively.

Heterosis for yield and yield contributing characters in cowpea genotypes

Fifteen F<sub>1</sub> hybrids obtained by crossing 6 diverse parental lines of cowpea through diallel excluding reciprocals method was studied to investigate the extent of heterosis for yield and yield contributing characters during <italic>kharif</italic>, 2007 and <italic>spring</italic><italic>summer</italic>, 2008 season. Among the various components pods per plant and seeds per pods are important factor contributing to yield. IT-97K-1042 and IT-93K-452 were observed to be the top performing parents for total seed yield per plant. The crosses IT-97K-1042 X IT-98K-1111 and IT-97K-1042 X Pusa Komal were best heterotic crosses for seed yield and other characters.

Studies on exploitation of heterosis in bottlegourd (Lagenaria siceraria (Mol) standI.)

The study was conducted in bottlegourd (Lagenaria siceraria (Mol.) Standl.) to investigate extent of heterosis for yield and its contributing characters with five parents and their 10 F, hybrids. Maximum heterosis over the better parent was expressed for fruit weight (108.3%) and fruit yield per vine (98.12%) in F, cross Pratik x TPT local while AB with TPT local and PSPL registered high heterobeltiosis for fruits per vine (22.95%) fruit girth (30.69%) and fruit flesh thickness (34.05%) respectively.

Evaluation of variability parameters, character association and genetic distance in Triticum durum genetic stocks

Genetic diversity was assessed in 42 genetic stocks of Triticum durum on the basis of 10 quantitative characters. High magnitude of variation was reflected by a wide range values for all the characters. Six characters i.e., days to heading, plant height, productive tillers per plant, 1000 grain weight, protein content and sedimentation value showed high heritability value which means that these characters are likely to respond to direct selection. Low correlation between 1000 grain weight and yield indicated that the role of 1000 grain weight in enhancing yield appeared to be limited in case of durum wheat and the two traits were behaving independently. Low negative correlation of yield with protein (-0.18) and no correlation with sedimentation value indicate the possibility of evolving varieties with high yield along with high protein content and strong gluten strength. Clusters formed revealed the absence of relationship between geographical distances and genetic divergence. Crossing between cultivars belonging to clusters I. V, VI and VII is expected to give mazimum extent of heterosis for yield.

EXPLOITATION OF HETEROSIS USING MALE STERILITY AND DIVERSE PLANT TYPES IN PIGEONPEA

The extent of heterosis for yield and yield and yield contributing components were studied in a set of 30 crosses involving a genetic male sterile line and 30 genetically diverse plant types of indeterminate and determinate types of Pigeonpea. Five cross combinations using male parents L.297, F21.M, OP.SP.L.Brown, S.Brown, L.298 and MS Prabhat. DT as female parent were identified as the best hybrids for grain yield on the per se performance with high heterotic expression. Development of hybrids using parental combination of determinate and indeterminate types would yield good hybrids vigour. High heterosis for traits like pods/plant, number of primary branches and grain/plant had influenced the grain yield.

HETEROSIS FOR YIELD AND YIELD COMPONENTS IN Sorghum bicolor (L) MOENCH

The extent of heterosis for yield and yield components in a set of eighty one cross combinations consisting of nine male sterile lines and nine restorer lines of Sorghum were studied. The cross combinations 2077A X Co 26, 296A X IL 101, 3002A X Co 25 and TNAU MS IA X IL 105 were identified as the best hybrids for grain yield on the basis of per se performance with high heterotic expression.

A. COMPARATIVE STUDY OF HETEROSIS IN HYBRIDS OF MALE STERILE LINES WITH INDIGENOUS SORGHUM CULTIVARS

The extent of heterosis for yield and yield attributes in a set of 30 cross combina- tions consisting of six male sterile and five indigenous restorer lines of sorghum were studied. Heterosis was observed in all the hybrids in respect of plant height. The maximum relative heterosis was recorded in the cross CK 60 Ax DSV 23 followed by 1036 A x Usilampatti 2. Twenty three hybrids manifesfed highly significant positive hetero- sis for panicle length. For single plant yield, five crosses 2758 A x K6, CK 60A x K6 10570A x Usilampatti 2, 10570A x DSV 23 and 2758A x Dindigul-1 recorded highly significant relative heterosis.

Heterosis and Combining Ability in a Diallel Cross of Onions1

Abstract Nine inbred onion (Allium cepa L.) lines of diverse origin and known horticultural performance were crossed in diallel to measure the extent of heterosis for yield and 6 other traits and to evaluate the types of gene action involved in character expression. Parents and the 36 F1 hybrids were compared at 2 locations (Michigan and Wisconsin) in 1975. Average performance of the parents and hybrids showed good agreement between environments for yield and several other traits. The mean performance of F1 hybrids fell within the range of parents for all characters. Although not always significant, F1’s on the average yielded more, were earlier to mature, had greater bulb weights, more centers, fewer rings, and were less firm than the average of the better parents in crosses. Heterosis was significant and favorable at both locations for yield, maturity, and bulb weight, but unfavorable for centers/bulb. Yield heterosis of the hybrids over the mid- and high parent, respectively, were 39 and 20% at Palmyra, Wisconsin and 27 and 12% at East Lansing, Michigan. In general, high F1 yields were associated with crosses involving high yielding parents. Variances of general combining ability (GCA) predominated for all traits. Small but significant specific combining ability (SCA) effects were noted for maturity, bulb firmness, and % of storage loss.

The expression of heterosis for yield in restored F1hybrid wheats and its interactions with seed rate and seed size

SummarySeed of nine F1hybrid wheat genotypes was produced by wind pollination. In one trial, grown at two seed rates, the extent of heterosis for yield and two yield components was small and was not affected by seed rate. In an adjacent trial the extent of heterosis in three hybrids was found to be affected by seed size.