95T1293 and 95T1184 heterozygous seedlings, along with the nearly isogenic control E6203, were
transplanted into field plots of 20 plants each at standard densities in the summer of 1996- The sites were in Akko,
Israel (IS); Badajoz, Spain (SP), Stockton, California (CAH); Woodland, California (CAP); and Numata, Japan
(JP). There were 3 reps of ms-10 heterozygous NILs and 9 reps of E6203 at each site. The only exception was JP
where there were 2 reps of the ms-10-NILs and 6 reps of E6203. Details of field condition and cultural practices
can be found in Tanksley et al. (1997). All plots were harvested at the end of the season and evaluated for the
traits listed in Table 1 as described in Tanksley et al. (1997). The only exception was for yield which was not
measured at CAH. Table 1 summarizes ANOVA's comparing performance of set of NILs for each trait.
The 95T1184 stock was most similar in performance to the E6203 control. It differed only marginally (P =
0.05-0.10) by having more growth and cover, slightly rounder fruit and a higher overall red yield (Table 1).
95T1293 had many more differences relative to E6203. Not only were the fruit rounder, but they were also
considerably heavier than E6203 and 95T1184 (approximately 10% heavier). They tended to be multilocular with
large stem scars and often took on the appearance of a fresh market type which would be unacceptable from a
processing viewpoint. 95T1293 also had a great total yield caused by an increased yield of green fruit. (Table 1).
95T1184 had fruit shape more rounded than a typical blocky E6203 fruit, but the shape still fell in the
range acceptable for processing tomatoes. The fact that both ms-10 NILs had fruit more round than E6203,
suggests that ms-10 is linked to a gene(s) controlling fruit shape. This result is consistent with the identification of
a fruit shape QTL in this same region of chromosome 2 (Ku and Tanksley, unpublished). ms-10 may also be
linked to a yield gene since this trait was affected (positively) in both NILs. Likewise a fruit weight gene may reside
in the same region of chromosome 2, since 95T1293 had much larger fruit. However, since 95T1184 had fruit
indistinguishable in size from E6203, we cannot rule out the possibility that this effect was due to some undesired
gene(s) which still remains from the donor line in 95T1293.
Because of associated fruit effects, 95T1293 is unlikely to be useful as a processing male-sterile type.
However, 95T1184 is similar enough in type to be acceptable for this purpose and may provide some added
benefit of a slight, but significant, increase in yield.
Literature cited:
Tanksley SD, Zamir D (1988) Double tagging of a male-sterile gene in tomato using a morphological and
enzymatic marker gene. HortScience 23:387-388
Tanksley SD et al. (1997) Yield and Quality Evaluations on a Pair of Processing Tomato Lines Nearly Isogenic for
the Tm2a Gene for Resistance to the Tobacco Mosaic Virus. Euphytica (submitted)
No navigation control above? Click here!