Year : 2005, Volume : 32, Issue : 3 and 4
Print ISSN : 0970-8235.
Selection of superior crosses on the basis of progeny mean in potato
Authors: Pande P.C., Luthra S.K., Singh B.P.1, Pandey S.K.2
1 Central Potato Research Institute Campus, Modipuram—250110, Meerut, UP, India
2Central Potato Research Institute, Shimla-171001, HP, India
In potato breeding programme, parents with desirable attributes are crossed to create genetic variability for selecting superior clones. Progeny tests were suggested (Brown and Caligari, 1988, Gopal 1997) to identify superior cross combinations. Large populations of identified crosses are raised for individual clone selection in segregating progenies. Progeny mean is the easiest parameter to be computed. It adequately reflects subsequent performance of the clones in advance generations (Bradshaw and Mackey, 1994).
In north-central plains of India, the main selection criteria in variety improvement programme are medium maturity, high productivity, good keeping quality and resistance to late blight. To identify superior crosses for large scale exploitation, 88 crosses (each represented by 30 progenies) were evaluated in F1C1 stage in 2003–2004 potato crop season at Meerut. The data were recorded on plant vigour, foliage maturity, late blight resistance and tuber yield. Sufficient late blight inoculum was present during second week of January, 2004 for proper assessment of late blight infection in the progenies. At harvest, selections were made on the basis of acceptable tuber attributes. The progeny means and character associations for various traits were also worked.
Based on acceptable tuber characters, selections were obtained from 56 crosses. The crosses giving high progeny mean for plant vigour, late blight resistance, tuber yield, and a higher percentage of superior selections within the cross, were identified (Table 1).
The highest percentage of selection was obtained from family Kufri Chipsona-1 x J92-111 (45%) followed by JN1752 x JEX/A-592 (44%), JX90 x JEX/A-1020 (36%), CP1338 x CP2013 (23%), JN1752 x CP3125 and JX90 x CP2013 (17%). Progenies of the families from crosses of Kufri Anand x CP3090, CP1358 x JEX/A-592 and SLB/ U-125 x JN2231 were free from late blight infection, whereas, families CP1909 x CP2013, JEM/O30 x CP2013, JI1857 x JN1197, MS/92-3128 x JEX/A-1192, Kufri Chipsona-1 x Kufri Anand, JF4841 x CP3125, JN1752 x JEX/ A-592, MS/92-3128 x JN1197, CP3356 x CP3125, JF4841 x JN1197, MS/83-279 x CP3125 and JX118 x JN1197 had about 95% progenies resistant to late blight. Highest family mean tuber yield was recorded in cross CP1358 x JEX/A-1192 (433 g/plant) followed by JF4841 x CP3125 (352 g/plant), JN1752 x JEX/A-592 (311 g/plant), CP1909 x JEX/A-592 (309 g/plant) and JN2207 x JEX/A-827 (297 g/plant).
Though superior crosses varied for different characters (Table 1), crosses JN1752 x JEX/A-592, Kufri Chipsona-1 x MS/82-717 and Kufri Anand x CP3090 were common for high tuber yield, per cent selection of superior clones and late blight resistance. For identifying promising crosses a criteria was fixed. This involved high progeny mean for plant vigour (vigrous), tuber yield (>225 g/plant), late blight resistance (>90% progenies) and per cent selection (10%). Based on this criteria, crosses CP1358 x JEX/A-1192, CP1909 x CP2013, JEM/O-30 x JN1197, JI1857 x JN1197, JN1752 x JEX/A-592, JN1752 x JN1197, JX90 x CP2013, Kufri Chipsona-1 x J92-111, Kufri Chipsona-1 x Kufri Anand and Kufri Anand x CP3090 were found superior. These crosses can be exploited for identifying high yielding varieties with late blight resistance under North-central plains of India.
The analysis of character associations among different traits showed positive and significant correlation of late blight resistance with plant vigour, foliage maturity, family mean tuber yield and per cent selection within the family (Table 2). Late foliage maturity was associated with high plant vigour. Families with high progeny mean tended to produce higher number of desirable selections as revealed by positive correlation of family mean tuber yield (0.50**) with per cent selection. The characters association results indicated that it is possible to select crosses for high values of important desirable characters like plant vigour, family mean tuber yield and late blight resistance to get high percentage of desirable selections in segregating populations.